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8.6 Blk reloading info
- Thread starter unclemoak
- Start date
Just some thoughts...
Here is the throat of a 308 Win after 8000rds.
I had very accurate records back then more than 25 yrs ago.
After every 500 rds I shoot a few 100 yds groups for short range accuracy.
The notes say 4, 3 shot groups averaged, .239" at 7000 rds.
And just shot a 2.422" 3 shot group at 1000 yds at 6900 rds.
5000 rds 1st shot hit on a quail at 1002 yds just behind the 1000yd lazered target.
5 into 6.140" 3 into 1.708" , 3 into 4.610".
3 shots were mostly practiced for sniper type crap on your belly shoot 3 shots move change location, from 800 to 1400 yds.
17,000 match rds later, ya tend to learn stuff.
Many years later took the 8,000 rd 308 barrel you see below and cut the chamber and throat off, shortened the overall length about 6". And decided to make an obsolete AR 15 30 RAR out of the 8000rd 308 barrel.
With old AR 15 spare parts and a finish chamber reamer it only cost $340 to build from scratch, including the new reamer which was half the cost. I profiled, chambered, threaded, turned gas journal, drilled gas port. Modified everything that needed it and put it together.
I remember the old 308 barrel loved Lapua 155s. SoI made the brass which has a .500 head dia, and loaded up some 155 icartridges, it shoots 1/2" or less groups on a 8000 rd barrel with most of the fire cracking gone this barrel is good for another 8000 rds...a total of 16,000 rds.
What is a 30 RAR?
It's the middle one larger in diameter than the 8.6 Blk on the left at .500" and 42.5 grs of H2O capacity its close to the capacity of the 8.6 around 46 gr H20, but the 30 RAR fits in an AR 15 just like the 338 Spectre on the right.
Just thoughts and tidbits about cartridges and barrel life...plus an opinion that may entertain.
Here is the throat of a 308 Win after 8000rds.
I had very accurate records back then more than 25 yrs ago.
After every 500 rds I shoot a few 100 yds groups for short range accuracy.
The notes say 4, 3 shot groups averaged, .239" at 7000 rds.
And just shot a 2.422" 3 shot group at 1000 yds at 6900 rds.
5000 rds 1st shot hit on a quail at 1002 yds just behind the 1000yd lazered target.
5 into 6.140" 3 into 1.708" , 3 into 4.610".
3 shots were mostly practiced for sniper type crap on your belly shoot 3 shots move change location, from 800 to 1400 yds.
17,000 match rds later, ya tend to learn stuff.
Many years later took the 8,000 rd 308 barrel you see below and cut the chamber and throat off, shortened the overall length about 6". And decided to make an obsolete AR 15 30 RAR out of the 8000rd 308 barrel.
With old AR 15 spare parts and a finish chamber reamer it only cost $340 to build from scratch, including the new reamer which was half the cost. I profiled, chambered, threaded, turned gas journal, drilled gas port. Modified everything that needed it and put it together.
I remember the old 308 barrel loved Lapua 155s. SoI made the brass which has a .500 head dia, and loaded up some 155 icartridges, it shoots 1/2" or less groups on a 8000 rd barrel with most of the fire cracking gone this barrel is good for another 8000 rds...a total of 16,000 rds.
What is a 30 RAR?
It's the middle one larger in diameter than the 8.6 Blk on the left at .500" and 42.5 grs of H2O capacity its close to the capacity of the 8.6 around 46 gr H20, but the 30 RAR fits in an AR 15 just like the 338 Spectre on the right.
Just thoughts and tidbits about cartridges and barrel life...plus an opinion that may entertain.
Attachments
Got a chance before the storm to shoot the 338 Spectre with pistol primers, using QL predicted data.
The 338 Spectre is more limited with large pistol primers in pressure so I put some max pressure loads together with LP primers.
I am impressed with the tiny velocity spread of just about all supers, fired in an AR 15, And loaded on a Dillon progressive with a case activated powder measure drop...no weighing of each charge...and single didget S/Ds is excellent.
That can be attributed to the higher load density of the tiny case, and the predicted 100% burn rate by QL.
Also note a predicted load velocity by QL and the actual velocities measured....
In high pressure supers QL predicition velocity was lower then measured velocities.
But on sub loads QL predicted higher velocities, than actual measured velocities with same powder. The inverse happens.
I would attribute that to the change in pressure causes a change in how well the powder burns, and its burn rate, even if it's a hundred percent burnt at low pressure.
So with LilGun I have to take out maybe three tenths of a grain on supers and add maybe half to eight tenths grain on subs ...in this cartridge only. But it's probably True for other cartridges as well depending on pressures and fill percentage, making 5hings more unpredictable with large swings in fill percentage.
Lots of interesting things happen when comparing cartridges same caliber but too large a powder space in the cartridge for subs and some supers VS a smaller cartridge that utilized most of the space.
Kinda proving what we already know.
And last but not least a 300 gr Maker Rex specifically made for 6.5 twist 338 Spectre shot at 961 fps muzzle (a bit low from QL prediction) into a wet dirt bank void of rocks.
Yeah I know it's not ballistics gel, and I ain't gonna hunt with it...but the dirt bank had nice fine moist dirt...so why not try it.
It worked as it should in this medium and spun around almost backward at the end of the dirt wound channel penetration was good.
But you hunters will have to actually preform your own test to satisfy yourselves before going hunting...this is just me shooting stuff, and here is the results of those tests.
A fun day shooting...
The 338 Spectre is more limited with large pistol primers in pressure so I put some max pressure loads together with LP primers.
I am impressed with the tiny velocity spread of just about all supers, fired in an AR 15, And loaded on a Dillon progressive with a case activated powder measure drop...no weighing of each charge...and single didget S/Ds is excellent.
That can be attributed to the higher load density of the tiny case, and the predicted 100% burn rate by QL.
Also note a predicted load velocity by QL and the actual velocities measured....
In high pressure supers QL predicition velocity was lower then measured velocities.
But on sub loads QL predicted higher velocities, than actual measured velocities with same powder. The inverse happens.
I would attribute that to the change in pressure causes a change in how well the powder burns, and its burn rate, even if it's a hundred percent burnt at low pressure.
So with LilGun I have to take out maybe three tenths of a grain on supers and add maybe half to eight tenths grain on subs ...in this cartridge only. But it's probably True for other cartridges as well depending on pressures and fill percentage, making 5hings more unpredictable with large swings in fill percentage.
Lots of interesting things happen when comparing cartridges same caliber but too large a powder space in the cartridge for subs and some supers VS a smaller cartridge that utilized most of the space.
Kinda proving what we already know.
And last but not least a 300 gr Maker Rex specifically made for 6.5 twist 338 Spectre shot at 961 fps muzzle (a bit low from QL prediction) into a wet dirt bank void of rocks.
Yeah I know it's not ballistics gel, and I ain't gonna hunt with it...but the dirt bank had nice fine moist dirt...so why not try it.
It worked as it should in this medium and spun around almost backward at the end of the dirt wound channel penetration was good.
But you hunters will have to actually preform your own test to satisfy yourselves before going hunting...this is just me shooting stuff, and here is the results of those tests.
A fun day shooting...
Attachments
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For those who want to try a more stable?...or maybe a different Maker Rex heavy bullet, the 300 gr 338 Spectre 6.5 twist is made for the 6.5 twist exclusively and ya get 50 bullets instead of 25 bullets in the box,...cheaper.
And a 305 gr, plus many others in the lighter grain weights..to try, but do pay attention to their recommendations as to what twist rate & velocity the bullet was actually designed for.
And a 305 gr, plus many others in the lighter grain weights..to try, but do pay attention to their recommendations as to what twist rate & velocity the bullet was actually designed for.
I’ll have to contact Redding, my die is leaving horrible scars from the start. I only sized 10 rounds and quit.
Hello everyone, new here, but been lurking for a few weeks doing some research. I just picked up a Faxon FX7 Barreled Action 16" 8.6 BLK 1:3 Twist on Black Friday, and pillared/glassed it into a Boyd featherweight stock. A lot of the posts in this thread made me have buyer's remorse, but I am happy to report that I have been having reasonable success chasing velocity with this cartridge in the 1:3 twist.
These are the very first cartridges fired from the rifle. I am using the Federal 225 to gather some data first as they were on sale for about $0.50 per bullet (and still might be) at Midway as factory overrun. I also have some 160 gr. TTSX I plan to do some testing with as well.
I originally followed the P-MAX Ballistic Calculator's pressure curve for monolithic. However, as I passed what should have been the max load (~65k psi) for a monolithic bullet without any indication of overpressure, I switched to using "Copper jacketed, lead core". I then did the same and changed to "Bore Rider with Drive band" as I passed the proposed pressure limit of 65k psi for that copper jacket pressure curve. All observations indicate that the bore rider with drive band is the appropriate curve for predictions, at least with this federal projectile. Therefore in the below table, I am showing P-Max's estimated velocity/pressures as well as the actual observed average velocities for a given charge weight. Velocities are in feet per second. 3 shot groups. I was shooting at an indoor range at 30 yards, so I wasn't concerned about testing accuracy, just chasing velocities at this time.
There looks to be a nice node at around ~32.5 gr of H335 for anyone who wants to run the Maker 220 gr T-Rex projectiles. SDs seem to tighten up at max fill. I was able to compress up to 37.6 gr of powder with my current seating depth, so there is room to go a little heavier with charges, but I'm not sure if I will... would like to get my hands on some Barne's and make sure the results are consistent.
Primers slowly flattened more and more going up the last ladder. Photo of the brass/primers are below as well from that last ladder. I included two cartridges from each series, vertically in the photo from left to right.
Rifle: Faxon FX7 Barreled Action 16" 8.6 BLK 1:3 Twist
(manufactured in October per inspection card)
Suppressor: SilencerCo 46 Hybrid M (full length) with .46 end cap
Chronograph: Magnetospeed v3
Powder: Hodgdon H335
Primer: WLR
Projectile: 225 gr. .338 Federal Trophy Copper Polymer Tip
Brass: Starline 8.6 Blackout (Bulk - 100)
Brass OAL: 1.685"
COAL: 2.725"
Case Capacity at COAL: 34.3 gr H2O (actual)
Jump: 0.051"
Die-Set: Lee 8.6 Blackout Pacesetter
I'm Curious to see what everyone's thoughts are on this given the 1:3 twist isn't the most loved...
These are the very first cartridges fired from the rifle. I am using the Federal 225 to gather some data first as they were on sale for about $0.50 per bullet (and still might be) at Midway as factory overrun. I also have some 160 gr. TTSX I plan to do some testing with as well.
I originally followed the P-MAX Ballistic Calculator's pressure curve for monolithic. However, as I passed what should have been the max load (~65k psi) for a monolithic bullet without any indication of overpressure, I switched to using "Copper jacketed, lead core". I then did the same and changed to "Bore Rider with Drive band" as I passed the proposed pressure limit of 65k psi for that copper jacket pressure curve. All observations indicate that the bore rider with drive band is the appropriate curve for predictions, at least with this federal projectile. Therefore in the below table, I am showing P-Max's estimated velocity/pressures as well as the actual observed average velocities for a given charge weight. Velocities are in feet per second. 3 shot groups. I was shooting at an indoor range at 30 yards, so I wasn't concerned about testing accuracy, just chasing velocities at this time.
There looks to be a nice node at around ~32.5 gr of H335 for anyone who wants to run the Maker 220 gr T-Rex projectiles. SDs seem to tighten up at max fill. I was able to compress up to 37.6 gr of powder with my current seating depth, so there is room to go a little heavier with charges, but I'm not sure if I will... would like to get my hands on some Barne's and make sure the results are consistent.
Primers slowly flattened more and more going up the last ladder. Photo of the brass/primers are below as well from that last ladder. I included two cartridges from each series, vertically in the photo from left to right.
Rifle: Faxon FX7 Barreled Action 16" 8.6 BLK 1:3 Twist
(manufactured in October per inspection card)
Suppressor: SilencerCo 46 Hybrid M (full length) with .46 end cap
Chronograph: Magnetospeed v3
Powder: Hodgdon H335
Primer: WLR
Projectile: 225 gr. .338 Federal Trophy Copper Polymer Tip
Brass: Starline 8.6 Blackout (Bulk - 100)
Brass OAL: 1.685"
COAL: 2.725"
Case Capacity at COAL: 34.3 gr H2O (actual)
Jump: 0.051"
Die-Set: Lee 8.6 Blackout Pacesetter
| Charge (gr) | S.D | Avg. Velocity | Est. Velocity | Est. Pressure PSI |
| 28.5 | 20.6 | 1624 | 1555 | 21769 |
| 29.0 | 9.25 | 1683 | 1591 | 23092 |
| 29.5 | 22 | 1707 | 1628 | 24499 |
| 30.0 | 9.1 | 1734 | 1665 | 25992 |
| (new ladder) 31.5 | 10.1 | 1796 | 1779 | 31100 |
| 32.0 | 10 | 1835 | 1818 | 33052 |
| 32.5 | 1.7 | 1883 | 1857 | 35142 |
| 33.0 | 4.4 | 1915 | 1896 | 37388 |
| 33.5 | 15.1 | 1942 | 1937 | 39809 |
| 34.0 | 13.7 | 1950 | 1977 | 42407 |
| (new ladder) 34.5 | 7.5 | 1961 | 2017 | 45217 |
| 35.0 | 5.1 | 1995 | 2058 | 48266 |
| 35.3 | 6.4 | 2012 | 2083 | 50220 |
| 35.6 c | 2.8 | 2024 | 2108 | 52256 |
| 35.8 c | 6.4 | 2030 | 2126 | 53710 |
| 36.0 c | 5.6 | 2045 | 2141 | 55185 |
| 36.3 c | 1.8 | 2055 | 2167 | 57514 |
| 36.6 c | 9.2 | 2065 | 2192 | 59956 |
I'm Curious to see what everyone's thoughts are on this given the 1:3 twist isn't the most loved...
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Change to 6.5 tw. Then keep having fun.Hello everyone, new here, but been lurking for a few weeks doing some research. I just picked up a Faxon FX7 Barreled Action 16" 8.6 BLK 1:3 Twist on Black Friday, and pillared/glassed it into a Boyd featherweight stock. A lot of the posts in this thread made me have buyer's remorse, but I am happy to report that I have been having reasonable success chasing velocity with this cartridge in the 1:3 twist.
These are the very first cartridges fired from the rifle. I am using the Federal 225 to gather some data first as they were on sale for about $0.50 per bullet (and still might be) at Midway as factory overrun. I also have some 160 gr. TTSX I plan to do some testing with as well.
I originally followed the P-MAX Ballistic Calculator's pressure curve for monolithic. However, as I passed what should have been the max load (~65k psi) for a monolithic bullet without any indication of overpressure, I switched to using "Copper jacketed, lead core". I then did the same and changed to "Bore Rider with Drive band" as I passed the proposed pressure limit of 65k psi for that copper jacket pressure curve. All observations indicate that the bore rider with drive band is the appropriate curve for predictions, at least with this federal projectile. Therefore in the below table, I am showing P-Max's estimated velocity/pressures as well as the actual observed average velocities for a given charge weight. Velocities are in feet per second. 3 shot groups. I was shooting at an indoor range at 30 yards, so I wasn't concerned about testing accuracy, just chasing velocities at this time.
There looks to be a nice node at around ~32.5 gr of H335 for anyone who wants to run the Maker 220 gr T-Rex projectiles. SDs seem to tighten up at max fill. I was able to compress up to 37.6 gr of powder with my current seating depth, so there is room to go a little heavier with charges, but I'm not sure if I will... would like to get my hands on some Barne's and make sure the results are consistent.
Primers slowly flattened more and more going up the last ladder. Photo of the brass/primers are below as well from that last ladder. I included two cartridges from each series, vertically in the photo from left to right.
Rifle: Faxon FX7 Barreled Action 16" 8.6 BLK 1:3 Twist
(manufactured in October per inspection card)
Suppressor: SilencerCo 46 Hybrid M (full length) with .46 end cap
Chronograph: Magnetospeed v3
Powder: Hodgdon H335
Primer: WLR
Projectile: 225 gr. .338 Federal Trophy Copper Polymer Tip
Brass: Starline 8.6 Blackout (Bulk - 100)
Brass OAL: 1.685"
COAL: 2.725"
Case Capacity at COAL: 34.3 gr H2O (actual)
Jump: 0.051"
Die-Set: Lee 8.6 Blackout Pacesetter
Charge (gr) S.D Avg. Velocity Est. Velocity Est. Pressure PSI 28.5 20.6 1624 1555 21769 29.0 9.25 1683 1591 23092 29.5 22 1707 1628 24499 30.0 9.1 1734 1665 25992 (new ladder)
31.510.1 1796 1779 31100 32.0 10 1835 1818 33052 32.5 1.7 1883 1857 35142 33.0 4.4 1915 1896 37388 33.5 15.1 1942 1937 39809 34.0 13.7 1950 1977 42407 (new ladder) 34.5 7.5 1961 2017 45217 35.0 5.1 1995 2058 48266 35.3 6.4 2012 2083 50220 35.6 c 2.8 2024 2108 52256 35.8 c 6.4 2030 2126 53710 36.0 c 5.6 2045 2141 55185 36.3 c 1.8 2055 2167 57514 36.6 c 9.2 2065 2192 59956
I'm Curious to see what everyone's thoughts are on this given the 1:3 twist isn't the most loved...
Yeah I'm not sure why someone would go 1/3 for supers
As a counterpoint, why use 8.6 BLK for sub-sonic? 8.6 BLK shines a dual-purpose cartridge, there are better cartridges for super-sonic use, and sub-sonic use respectively, as evidenced by this very thread.
I definitely will be using the gun for both supers and subs, I’m out in Wisconsin so max ranges for hunting are 150ish yards most of the time. Also, I picked up the barreled action for less than $700 shipped! The way I see it, I got a custom action with a free 8.6, 1:3 twist barrel!
Will change out to 1:6.5 tw down the road if I start hitting a wall with my satisfaction. But I doubt I will, part of the fun is seeing how much performance you can get out of what you have, right? To answer your question about why I went for 1:3, the answer is, "to have fun" 
.So far, not many folks have posted successful charges in 1:3, and as far as I can tell most people hit pressure signs early when working up loads for 1:3. I used many of those posts in this thread as a reference for my own starting points... My post is more along the lines of evidence of what might be possible in a 1:3 with similar components since I didn’t see many other positive stories. Putting my data/information out here for others who may benefit as well, setting a potential new starting point for someone new to the cartridge (like me), in its most ubiquitous configuration.
Additionally, this data is usable for 1:6.5 and of course, will yield better performance out of that barrel. Just adding to the stockpile of information someone might find useful!
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Do you have an Anchor brake for your Hybrid46? Curious if you do, how it mitigates recoil on your super loads?Hello everyone, new here, but been lurking for a few weeks doing some research. I just picked up a Faxon FX7 Barreled Action 16" 8.6 BLK 1:3 Twist on Black Friday, and pillared/glassed it into a Boyd featherweight stock. A lot of the posts in this thread made me have buyer's remorse, but I am happy to report that I have been having reasonable success chasing velocity with this cartridge in the 1:3 twist.
These are the very first cartridges fired from the rifle. I am using the Federal 225 to gather some data first as they were on sale for about $0.50 per bullet (and still might be) at Midway as factory overrun. I also have some 160 gr. TTSX I plan to do some testing with as well.
I originally followed the P-MAX Ballistic Calculator's pressure curve for monolithic. However, as I passed what should have been the max load (~65k psi) for a monolithic bullet without any indication of overpressure, I switched to using "Copper jacketed, lead core". I then did the same and changed to "Bore Rider with Drive band" as I passed the proposed pressure limit of 65k psi for that copper jacket pressure curve. All observations indicate that the bore rider with drive band is the appropriate curve for predictions, at least with this federal projectile. Therefore in the below table, I am showing P-Max's estimated velocity/pressures as well as the actual observed average velocities for a given charge weight. Velocities are in feet per second. 3 shot groups. I was shooting at an indoor range at 30 yards, so I wasn't concerned about testing accuracy, just chasing velocities at this time.
There looks to be a nice node at around ~32.5 gr of H335 for anyone who wants to run the Maker 220 gr T-Rex projectiles. SDs seem to tighten up at max fill. I was able to compress up to 37.6 gr of powder with my current seating depth, so there is room to go a little heavier with charges, but I'm not sure if I will... would like to get my hands on some Barne's and make sure the results are consistent.
Primers slowly flattened more and more going up the last ladder. Photo of the brass/primers are below as well from that last ladder. I included two cartridges from each series, vertically in the photo from left to right.
Rifle: Faxon FX7 Barreled Action 16" 8.6 BLK 1:3 Twist
(manufactured in October per inspection card)
Suppressor: SilencerCo 46 Hybrid M (full length) with .46 end cap
Chronograph: Magnetospeed v3
Powder: Hodgdon H335
Primer: WLR
Projectile: 225 gr. .338 Federal Trophy Copper Polymer Tip
Brass: Starline 8.6 Blackout (Bulk - 100)
Brass OAL: 1.685"
COAL: 2.725"
Case Capacity at COAL: 34.3 gr H2O (actual)
Jump: 0.051"
Die-Set: Lee 8.6 Blackout Pacesetter
Charge (gr) S.D Avg. Velocity Est. Velocity Est. Pressure PSI 28.5 20.6 1624 1555 21769 29.0 9.25 1683 1591 23092 29.5 22 1707 1628 24499 30.0 9.1 1734 1665 25992 (new ladder)
31.510.1 1796 1779 31100 32.0 10 1835 1818 33052 32.5 1.7 1883 1857 35142 33.0 4.4 1915 1896 37388 33.5 15.1 1942 1937 39809 34.0 13.7 1950 1977 42407 (new ladder) 34.5 7.5 1961 2017 45217 35.0 5.1 1995 2058 48266 35.3 6.4 2012 2083 50220 35.6 c 2.8 2024 2108 52256 35.8 c 6.4 2030 2126 53710 36.0 c 5.6 2045 2141 55185 36.3 c 1.8 2055 2167 57514 36.6 c 9.2 2065 2192 59956
I'm Curious to see what everyone's thoughts are on this given the 1:3 twist isn't the most loved...
I don't on my Hybrid but I do on my Omega 300. Has noticeable recoil reduction on high-pressure/high-velocity rounds. I do however regret using it while hunting this year, as it caused the direction of the sound to echo around me in the woods, blasting my ear. Flat front cap is better for sound reduction to the shooter.
Rifle: Faxon FX7 Barreled Action 16" 8.6 BLK 1:3 Twist
Suppressor: SilencerCo 46 Hybrid Modular (full length) with .46 end cap
Chronograph: Magnetospeed v3
Powder: Hodgdon H335
Projectile: 160 gr. .338 Barnes TTSX
Brass: Starline 8.6 Blackout (Bulk - 100)
Brass (Trim) OAL: 1.685"
COAL: 2.6965"
Case Capacity at COAL: 41.9 gr H2O (actual)
Jump: 0.050"
Die-Set: Lee 8.6 Blackout Pacesetter
I performed some more load testing that, for me at least, is starting to vindicate the 1:3 twist in a short(er) barrel configuration. No pressure signs, all the way to max. The results and performance is in line with what other users on this very thread have achieved with long barrels (24") in 1:6.5 twist. See below P-Max calculator screenshots for a comparison between 16" and 24" velocities.
For me, this opens up the viability of the 1:3 twist as a solid supersonic contender for medium sized game under 350 yards. With this load, minimum expansion can be achieved out to 330 yards (1,800 fps), not accounting for the fact that the projectile is also spinning at around 620,000 RPM which should have explosive expansion on target, and also cause it to expand a bit under 1,800 fps as well.
Sure, the 1:6.5 twist will have better ballistics, higher velocity therefore reach out further...etc, but for a true dual purpose rifle with an emphasis on the subsonic side, I think the 1:3 twist is very compelling. My point being that 1:3 is not a mistake for supersonic as many have alluded to, but rather a viable choice for the user who wants excellent subsonic performance with occasional but viable supersonic performance, in a short, lightweight package. This kind of capability is pretty much perfect for mid-western hunters like myself, where short + lightweight (blinds + tree stands) outweighs reach.
I do think, however, that the Barnes 185 gr. TTSX will be in the sweet spot of velocity, energy, and drag for this rifle. I need to get my hands on some of those and do some testing, more to come and I will share that information after the holidays. H335 seems to be the powder for 8.6 BLK to keep pressure low and run higher velocities with heavier projectiles.
Additionally, I want to point out that P-Max has been absolutely nailing the calculations, and that the results line up extremely well with real-world data.
P-Max comparison to actual data for this load
16 inch barrel P-Max Calculation
24 inch barrel P-Max Calculation
Suppressor: SilencerCo 46 Hybrid Modular (full length) with .46 end cap
Chronograph: Magnetospeed v3
Powder: Hodgdon H335
Projectile: 160 gr. .338 Barnes TTSX
Brass: Starline 8.6 Blackout (Bulk - 100)
Brass (Trim) OAL: 1.685"
COAL: 2.6965"
Case Capacity at COAL: 41.9 gr H2O (actual)
Jump: 0.050"
Die-Set: Lee 8.6 Blackout Pacesetter
| Charge (gr) | Quantity | Avg. Velocity | Max. Velocity | SD | Est. Velocity | Est. Pressure PSI |
|---|---|---|---|---|---|---|
| 42 | 3 | 2,406 | 2,416 | 10.0 | 2,319 | 37,167 |
| 43 (c) | 3 | 2,469 | 2,473 | 4.2 | 2,404 | 41,199 |
| 44 (c) | 3 | 2,509 | 2,519 | 8.3 | 2,489 | 45,798 |
| 44.5 (c) | 3 | 2,537 | 2,553 | 13.3 | 2,535 | 48,317 |
| 44.8 (c) | 3 | 2,549 | 2,561 | 10.6 | 2,560 | 49,943 |
| 45.1 (c) | 3 | 2,577 | 2,581 | 4.2 | 2,588 | 51,630 |
| 45.4 (c) | 3 | 2,588 | 2,591 | 2.4 | 2,615 | 53,384 |
I performed some more load testing that, for me at least, is starting to vindicate the 1:3 twist in a short(er) barrel configuration. No pressure signs, all the way to max. The results and performance is in line with what other users on this very thread have achieved with long barrels (24") in 1:6.5 twist. See below P-Max calculator screenshots for a comparison between 16" and 24" velocities.
For me, this opens up the viability of the 1:3 twist as a solid supersonic contender for medium sized game under 350 yards. With this load, minimum expansion can be achieved out to 330 yards (1,800 fps), not accounting for the fact that the projectile is also spinning at around 620,000 RPM which should have explosive expansion on target, and also cause it to expand a bit under 1,800 fps as well.
Sure, the 1:6.5 twist will have better ballistics, higher velocity therefore reach out further...etc, but for a true dual purpose rifle with an emphasis on the subsonic side, I think the 1:3 twist is very compelling. My point being that 1:3 is not a mistake for supersonic as many have alluded to, but rather a viable choice for the user who wants excellent subsonic performance with occasional but viable supersonic performance, in a short, lightweight package. This kind of capability is pretty much perfect for mid-western hunters like myself, where short + lightweight (blinds + tree stands) outweighs reach.
I do think, however, that the Barnes 185 gr. TTSX will be in the sweet spot of velocity, energy, and drag for this rifle. I need to get my hands on some of those and do some testing, more to come and I will share that information after the holidays. H335 seems to be the powder for 8.6 BLK to keep pressure low and run higher velocities with heavier projectiles.
Additionally, I want to point out that P-Max has been absolutely nailing the calculations, and that the results line up extremely well with real-world data.
P-Max comparison to actual data for this load
16 inch barrel P-Max Calculation
24 inch barrel P-Max Calculation
I already did all that testing with the 3 twist when they first came out from Faxon.
The barrel is off the gun for a fairly long time and I will never go back to the 3 twist.
Barrel quality from Faxon was horrendous, when they brought out the first 3T huge pits, torn & galled rifling.
Your barrel may be of better quality hopefully, maybe they learned how to do the 3T better.
I have purchased a Faxon 450 bushmaster barrel twice because the first was bad rifling and inaccurate, the 2nd was a little better.
I will not recommend their barrels or the limited 3 T barrel.
Hornady is running an 8T on their 338 ARC...ever wonder why?
They have deep pockets and lots of testing equipment, plus bullet manufacturers to find the best combination.
I run the 6.5 twist, now on my 8.6 Blk after wasting countless dollars and time shooting the 3T...trying to make it work.
Damaging my muzzle devices, the magneto speed bayonet, working with the 3T and found it inaccurate and dangerous with lead jacketed bullets.
None of that occurs with tbe 6.5 twist, accuracy, much higher super velocities, and the total use of All bullets at their max velocities, the 3T does not measure up for versatility.
A 24" bolt gun I run cheap jacketed 200 gr Speer hot core at 2600 fps, 160 gr Barnes TTSX to 2800 fps, 300 gr Berger at 1943 fps, 350 gr Maker limited to 1000 fps by manufacturer in 3T runs ...but runs 1675 fps in 6.5 twist...as a few examples, why I do not recommend the 3 twist to anyone...I've been there done that.
But if you like yours keep shooting it and thanks for the effort in load development for the 3T, but I've already done that, and moved on.
H335 is a good powder for the 8.6 Blk in both twists but just like my earlier testing, you also confirmed the 3T can not match the super velocities of the 6.5 twist by hundreds of feet per second in most cases, and not even close with lead jacketed bullets or speed limited Maker subs like 1050 fps 3T vs 1675 fps 6.5 T with 350 grs.
That alone plus the accuracy increase is why my experience, with both twist rates, tells me to push people away from the 3 T.
For subs only, for me, I've shooting the 338 Spectre, while waiting on tbe 338 ARC reamer, for some time in tbe AR 15.
The tiny 338 Spectre has been very accurate, & very consistent, single digit velocity S/Ds plus a lighter AR 15 platform, with its 6.5 T barrel shooting everything from 160 Barnes to 350 gr Maker.
The 350 gr is a lot of bullet for this tiny case and Maker makes a 300 gr that's better suited and specifically made for it plus their Super Expanding 165 gr at 2100 fps might give one extra desired range.
Plus Hornady the the very similar 338 ARC coming one of these days, I already have the cases.
This should be a very accurate sub gun for the light AR platform and short barrels.
They are 8 twist barels with their two loads a 307 gr sub, which should expand at sub velocities, can also be utilized in the 338 Spectre, 6.5 T. But the 3 T, who knows?
Hornady engineers laughed at the ridiculous 3 T on video, and went with 8 T, which highly irritated "one" person.
After spending a ton of time and money on the 338 sub/ super combo, it's not easy to do both with the best outcome of either...but the 6.5 twist is a huge plus.
I believe the best subs, are the small capacity cases, like the 338 ARC or 338 Spectre are the way to go for subsonic shooting.
The 338 Spectre that I have in AR 15 is an absolute blast, super accurate, shoot the eye out of a hog at 75 yards all ten rds.
I expect the same from the 338 ARC.
But neither is much of a super cartridge.
The 165 gr at 2100 fps that's supposed to expand at 900 fps may be the LR bullet for these tiny cases.
The barrel is off the gun for a fairly long time and I will never go back to the 3 twist.
Barrel quality from Faxon was horrendous, when they brought out the first 3T huge pits, torn & galled rifling.
Your barrel may be of better quality hopefully, maybe they learned how to do the 3T better.
I have purchased a Faxon 450 bushmaster barrel twice because the first was bad rifling and inaccurate, the 2nd was a little better.
I will not recommend their barrels or the limited 3 T barrel.
Hornady is running an 8T on their 338 ARC...ever wonder why?
They have deep pockets and lots of testing equipment, plus bullet manufacturers to find the best combination.
I run the 6.5 twist, now on my 8.6 Blk after wasting countless dollars and time shooting the 3T...trying to make it work.
Damaging my muzzle devices, the magneto speed bayonet, working with the 3T and found it inaccurate and dangerous with lead jacketed bullets.
None of that occurs with tbe 6.5 twist, accuracy, much higher super velocities, and the total use of All bullets at their max velocities, the 3T does not measure up for versatility.
A 24" bolt gun I run cheap jacketed 200 gr Speer hot core at 2600 fps, 160 gr Barnes TTSX to 2800 fps, 300 gr Berger at 1943 fps, 350 gr Maker limited to 1000 fps by manufacturer in 3T runs ...but runs 1675 fps in 6.5 twist...as a few examples, why I do not recommend the 3 twist to anyone...I've been there done that.
But if you like yours keep shooting it and thanks for the effort in load development for the 3T, but I've already done that, and moved on.
H335 is a good powder for the 8.6 Blk in both twists but just like my earlier testing, you also confirmed the 3T can not match the super velocities of the 6.5 twist by hundreds of feet per second in most cases, and not even close with lead jacketed bullets or speed limited Maker subs like 1050 fps 3T vs 1675 fps 6.5 T with 350 grs.
That alone plus the accuracy increase is why my experience, with both twist rates, tells me to push people away from the 3 T.
For subs only, for me, I've shooting the 338 Spectre, while waiting on tbe 338 ARC reamer, for some time in tbe AR 15.
The tiny 338 Spectre has been very accurate, & very consistent, single digit velocity S/Ds plus a lighter AR 15 platform, with its 6.5 T barrel shooting everything from 160 Barnes to 350 gr Maker.
The 350 gr is a lot of bullet for this tiny case and Maker makes a 300 gr that's better suited and specifically made for it plus their Super Expanding 165 gr at 2100 fps might give one extra desired range.
Plus Hornady the the very similar 338 ARC coming one of these days, I already have the cases.
This should be a very accurate sub gun for the light AR platform and short barrels.
They are 8 twist barels with their two loads a 307 gr sub, which should expand at sub velocities, can also be utilized in the 338 Spectre, 6.5 T. But the 3 T, who knows?
Hornady engineers laughed at the ridiculous 3 T on video, and went with 8 T, which highly irritated "one" person.
After spending a ton of time and money on the 338 sub/ super combo, it's not easy to do both with the best outcome of either...but the 6.5 twist is a huge plus.
I believe the best subs, are the small capacity cases, like the 338 ARC or 338 Spectre are the way to go for subsonic shooting.
The 338 Spectre that I have in AR 15 is an absolute blast, super accurate, shoot the eye out of a hog at 75 yards all ten rds.
I expect the same from the 338 ARC.
But neither is much of a super cartridge.
The 165 gr at 2100 fps that's supposed to expand at 900 fps may be the LR bullet for these tiny cases.
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Thanks for sharing your experiences, it was actually your earlier posts that were the basis of the loads that I'm working on right now. It’s clear you’ve done a ton of work testing both the 3T and 6.5T setups, and I respect the effort you’ve put in to get the best performance. I agree that the 1:3 twist is a niche chambering—it doesn’t match the versatility of the 6.5T for supers or lighter bullets. That said, it offers unique advantages for specific use cases like heavy subsonic and monolithic bullets where stabilization and terminal performance matter more than outright velocity.
I also wanted to point out that in my testing, I hit 2600 FPS with a 160-grain Barnes TTSX out of my 16-inch barrel. That matches the velocities you mentioned of 2800 fps for your 24-inch barrel after adjusting for barrel length, see the calculator screenshots (velocity on the far right).
This shows that the 1:3 twist can be used to achieve sufficient supersonic velocities. Additionally, I want to address a common misconception that I see with 8.6 BLK and fast twist in general. Fast twist isn’t inherently slower—it’s just redistributing some of the forward energy into rotational energy.
One factor contributing to the velocity difference we observe is bullet weight. Heavier bullets, like a 225-grain compared to a 160-grain, as we know, require significantly more force to accelerate. In a 1:3 twist barrel, this difference is amplified because of the increased torque needed to spin the heavier bullet against the sharper rifling. The torque required to spin a bullet scales with its rotational inertia, which depends on both its mass and radius: Torque ∝ Mass × Radius². A 225-grain bullet has about 40% more mass than a 160-grain bullet, resulting in a significant increase in torque requirements to spin the bullet at that twist rate. In a fast twist barrel like 1:3, some of the energy is diverted to overcome this increased torque demand, which lowers forward velocity. However, this energy is not entirely wasted—a lot of it is converted into rotational energy (I'm not a Q-Fan Boy, but their marketing is still based in science). There’s a common misconception that the 1:3 twist wastes a significant amount energy compared to a slower twist like the 1:6.5. That’s not quite true—the total energy of the bullet should similar in either twist rate (slightly slower in 1:3 as there is more friction), but the energy is split differently. In a faster twist barrel, velocity (and forward kinetic energy) is slightly reduced because some of this energy is diverted to rotational energy: E_total = E_kinetic + E_rotational. Whether or not the rotational energy has an advantage is still up for debate, and we can all draw our own conclusions on that. What I believe happens, however, is that when those heavier projectiles are traveling down the barrel in a fast twist, they hit a wall in torque requirement. I think the pressure generated in standard cartridges (60k-ish PSI) pushing the bullet cannot overcome this rising rotational inertia requirement, and thus you see marginal fps gains past a certain point in these heavy projectiles. I don't think this is as big of an issue in lighter projectiles, as evidenced by the performance I was able to achieve today with the 160 Barnes TTSX. That 40% more mass causes a huge spike in rotational energy demands throughout the entire acceleration of the bullet. So in my opinion, in 1:3 twist, lighter is better for super sonic if your goal is velocity.
Rotational Energy:
E_rotational = (1/2) * I * ω²
Where:
- I = (1/2) * m * r² (moment of inertia for a cylinder-shaped bullet)
- m = mass of the bullet (in kilograms)
- r = radius of the bullet (in meters)
- ω = (2 * π * RPM) / 60 (angular velocity in radians per second)
I also wanted to address the definition of versatility because I think we’re approaching it from different angles. You’re talking about versatility in terms of potential load combinations and how the platform can be optimized for velocity and accuracy from a reloading/gunsmithing perspective. For me, versatility is about the cartridge’s application in the field—short barrel, under 300 yards, and the ability to run both supersonic ammunition and heavy subsonic loads. From a pure hunting perspective, that’s where I see the 8.6 BLK shine. I might be out in the woods and make game time decisions and choose to hunt a close range sit of 50-75 yards, or depending on the conditions/movement of game, I might need to stretch the rifle out to 200 yards. I don't want to carry two different guns depending on the conditions for the day, but two different types of ammunition is perfectly fine by me. To me, that's what versatility is, being able to do what I just described, out of a highly maneuverable, short barrel weapon, with a suppressor.
For any other application outside of hunting, I'm not sure why to even bother with 8.6 BLK, outside of just experimenting and having fun.
I do think that your 1:3 barrel from Faxon was a bad one. I’ve seen reports of quality control issues early on, but my FX-7 was manufactured in October, and has been nothing but flawless. I had my gunsmith who builds precision rifles for competition inspect the barrel, and he said "yeah it's pretty okay", which by my standards means it's probably pretty nice. (He didn't like the tooling marks on the action, for those who are considering buying an FX7, it shoots fine though). I think they’ve refined their manufacturing since the earlier production runs.
Finally, I am curious—why did you choose a 24-inch barrel for 8.6 BLK? It’s great to see what you’ve achieved, but with that length, I'm not sure where the desire to have subsonic capability comes in with a barrel that long. And if there is no sub-sonic desire, then why not just use .338 Federal instead of 8.6 BLK? Was it for experimentation or were you targeting specific performance goals?
I feel as though we agree that there are better cartridges for specific use cases. I plan on adding a .338 Arc to my arsenal for pure sub-sonic use. But that isn't what I got the 8.6 BLK for. I got it to do either subsonic or supersonic, at a moments notice, when the duty calls. And as far as I am aware, that was the original goal and vision behind the cartridge.
I appreciate the dialogue—it’s great to hear from someone who’s done extensive testing with both twists. While I’m sticking with the 1:3 for my specific use case, which again is hunting under 300 yards, out of tree stands and blinds, where the guns overall length with a suppressor is critical for maneuverability, and a few bucks more on monolothic ammo doesn't mean much in the grand scheme of hunting. I completely understand why others might prefer the 1:6.5 for its versatility in load development. At the end of the day, it’s about matching the outcomes to your goals.
Curious why the 24" barrel, because the Faxon 3 T was a 16" and the new 338 barrel blank ordered with a 24" 6.5 T and chambered with my own reamer to fit a bolt action Rem 700.
I left it 24" to see how close it would come to the 338 Federal printed in the loading manuals, with actual barrels for the 338 Federal being 24" and 26" 10 Twist.
Depending on the manual it's very close to the 338 Frderal and within 50 fps if the Hornady manual which has a 26" barrel.
Plus I can shoot 300 gr Bergers over 1940 fps for Longer range plinking with accuracy...or very accurate subs with the long barrel.
It's 338 Federal velocity plus a better sub caliber than the 338 Federal.
Another large plus I can use cheap jacketed lead bullets for super or sub, not confined to expensive copper and special copper subs.
The 24" bolt gun is very versitle over 3000 ft/ lbs of killing energy with jacketed lead bullets just like the 338 Federal....300 yds easy.
Subsonic hunting is not "my thing", as I've said before... I ain't gonna kill any big game with subs... I have a .510 Whisper with 750 to 900 gr Makers if I was.
I have shot a bunch of Maker sub bullets to see how they performed mostly for accuracy and what velocities I could push them in the 6.5 T.
That was 650 fps faster in the 6.5 T for the 350 gr bullet past what is recommended for the 3 twist, cause the actually blow off the petals before reaching the target, in the 3 T.
That's a bunch more energy dumped into a game animal but it's supersonic... but if your sub loads aren't killing well dump a ton more energy into the target, with most any bullet available in 338 nothing special needed...a big advantage, in versatility of the 6.5 T.
The case is small enough to shoot subs reasonably accurate and large enough to complete with the 338 Federal.
I'm more interested in the 300 gr match bullets, where I can push them to close to 2000 fps if needed for LR plinking, a better option than the 338.
I waste hundreds of dollars on Maker & copper bullets and post some of the load information and experiences with the 8.6 Blk to share, what I've learned, and give others a starting point for their endeavors...I'm not gonna hunt with the 8.6 Blk, never considered it, even though I've shot a bunch of hunting bullets, even tested a few for expansion but not in ballistics gel...which many didn't like, because of varied results with different mediums.
As I've said, the bullet expansion testing is on you to decide if that bullet is right for your hunting needs, and report back to others who hunt to gain a consensus on what works for your particular type of hunting and twist rate, for the 8.6
As I've said before if you're happy with your 3 twist run it, if after awhile you want to try a 6.5 twist do that. Personal preference to fit your needs.
And the long barrel, 300 gr Berger or Sierra bullets, and 6.5T fit my needs because I'm not hunting or climbing into tree stands with it. But prone target shooting, with both subs and supers.
I left it 24" to see how close it would come to the 338 Federal printed in the loading manuals, with actual barrels for the 338 Federal being 24" and 26" 10 Twist.
Depending on the manual it's very close to the 338 Frderal and within 50 fps if the Hornady manual which has a 26" barrel.
Plus I can shoot 300 gr Bergers over 1940 fps for Longer range plinking with accuracy...or very accurate subs with the long barrel.
It's 338 Federal velocity plus a better sub caliber than the 338 Federal.
Another large plus I can use cheap jacketed lead bullets for super or sub, not confined to expensive copper and special copper subs.
The 24" bolt gun is very versitle over 3000 ft/ lbs of killing energy with jacketed lead bullets just like the 338 Federal....300 yds easy.
Subsonic hunting is not "my thing", as I've said before... I ain't gonna kill any big game with subs... I have a .510 Whisper with 750 to 900 gr Makers if I was.
I have shot a bunch of Maker sub bullets to see how they performed mostly for accuracy and what velocities I could push them in the 6.5 T.
That was 650 fps faster in the 6.5 T for the 350 gr bullet past what is recommended for the 3 twist, cause the actually blow off the petals before reaching the target, in the 3 T.
That's a bunch more energy dumped into a game animal but it's supersonic... but if your sub loads aren't killing well dump a ton more energy into the target, with most any bullet available in 338 nothing special needed...a big advantage, in versatility of the 6.5 T.
The case is small enough to shoot subs reasonably accurate and large enough to complete with the 338 Federal.
I'm more interested in the 300 gr match bullets, where I can push them to close to 2000 fps if needed for LR plinking, a better option than the 338.
I waste hundreds of dollars on Maker & copper bullets and post some of the load information and experiences with the 8.6 Blk to share, what I've learned, and give others a starting point for their endeavors...I'm not gonna hunt with the 8.6 Blk, never considered it, even though I've shot a bunch of hunting bullets, even tested a few for expansion but not in ballistics gel...which many didn't like, because of varied results with different mediums.
As I've said, the bullet expansion testing is on you to decide if that bullet is right for your hunting needs, and report back to others who hunt to gain a consensus on what works for your particular type of hunting and twist rate, for the 8.6
As I've said before if you're happy with your 3 twist run it, if after awhile you want to try a 6.5 twist do that. Personal preference to fit your needs.
And the long barrel, 300 gr Berger or Sierra bullets, and 6.5T fit my needs because I'm not hunting or climbing into tree stands with it. But prone target shooting, with both subs and supers.
A lot to read and sift through. I was just about to load supers with H335 in my 1:3 barrel, thanks. GRT is estimating most loads with H335 to have a low burn rate (highest I can get with different configurations is 80%). Based off of what I’m gathering from other users is this is the best powder for SuperSonics in regard to accuracy and velocity. Have you noticed unburnt powder in H335 loads?Rifle: Faxon FX7 Barreled Action 16" 8.6 BLK 1:3 Twist
Suppressor: SilencerCo 46 Hybrid Modular (full length) with .46 end cap
Chronograph: Magnetospeed v3
Powder: Hodgdon H335
Projectile: 160 gr. .338 Barnes TTSX
Brass: Starline 8.6 Blackout (Bulk - 100)
Brass (Trim) OAL: 1.685"
COAL: 2.6965"
Case Capacity at COAL: 41.9 gr H2O (actual)
Jump: 0.050"
Die-Set: Lee 8.6 Blackout Pacesetter
Charge (gr) Quantity Avg. Velocity Max.
VelocitySD Est. Velocity Est. Pressure PSI 42 3 2,406 2,416 10.0 2,319 37,167 43 (c) 3 2,469 2,473 4.2 2,404 41,199 44 (c) 3 2,509 2,519 8.3 2,489 45,798 44.5 (c) 3 2,537 2,553 13.3 2,535 48,317 44.8 (c) 3 2,549 2,561 10.6 2,560 49,943 45.1 (c) 3 2,577 2,581 4.2 2,588 51,630 45.4 (c) 3 2,588 2,591 2.4 2,615 53,384
I performed some more load testing that, for me at least, is starting to vindicate the 1:3 twist in a short(er) barrel configuration. No pressure signs, all the way to max. The results and performance is in line with what other users on this very thread have achieved with long barrels (24") in 1:6.5 twist. See below P-Max calculator screenshots for a comparison between 16" and 24" velocities.
For me, this opens up the viability of the 1:3 twist as a solid supersonic contender for medium sized game under 350 yards. With this load, minimum expansion can be achieved out to 330 yards (1,800 fps), not accounting for the fact that the projectile is also spinning at around 620,000 RPM which should have explosive expansion on target, and also cause it to expand a bit under 1,800 fps as well.
Sure, the 1:6.5 twist will have better ballistics, higher velocity therefore reach out further...etc, but for a true dual purpose rifle with an emphasis on the subsonic side, I think the 1:3 twist is very compelling. My point being that 1:3 is not a mistake for supersonic as many have alluded to, but rather a viable choice for the user who wants excellent subsonic performance with occasional but viable supersonic performance, in a short, lightweight package. This kind of capability is pretty much perfect for mid-western hunters like myself, where short + lightweight (blinds + tree stands) outweighs reach.
I do think, however, that the Barnes 185 gr. TTSX will be in the sweet spot of velocity, energy, and drag for this rifle. I need to get my hands on some of those and do some testing, more to come and I will share that information after the holidays. H335 seems to be the powder for 8.6 BLK to keep pressure low and run higher velocities with heavier projectiles.
Additionally, I want to point out that P-Max has been absolutely nailing the calculations, and that the results line up extremely well with real-world data.
P-Max comparison to actual data for this load
16 inch barrel P-Max Calculation
24 inch barrel P-Max Calculation
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Only very little unburnt powder if any at the lower charges for 160 gr., the heavier charges seem to generate enough pressure up front to burn the powder efficiently. I'm guessing GRT is off, as H335 is also used for 338 Federal normally. P-Max shows a 95-99% burn for these loads, if you look at the screenshot in my post I have the max charge with a burn of 96%. I do think H335 is a little bit slow of a powder for 160 gr in a short barrel, but there aren't many other powders that have similar pressure profiles, and load density, where you can just shove as much powder as you can fit into the case and send it down range without it turning into a grenade. Ramshot X-Terminator seems to have a similar density and burn rate, but I haven't played with it myself.
I also recommend measuring your case capacity at your seating depth, and to factor that into the calculations if you haven't yet. I don't recommend starting at
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I got my hands on a box of .338 200gr Hornady SST's and would appreciate some recommendations for which powder to use with them. I want to produce both sub and supersonic loads with this bullet and powder combo. It's fine if one powder is recommended for the sub load and a different powder is recommended for the SS loads. Finally, standard or magnum primer for each. (Barrel is 1:6.5) TIA!
I don’t think those bullets have been mentioned. For supers, they H335 and start at around 35gr and work up. I have ttsx 225 at 37gr with alpha brass in a 1:5 twist 16” barrel.
As for a sub load, I’d go heavier bullet. But if you insist on a 200gr bullet sub load. Try H110. As for a number, no one has really worked up a sub load for such a light bullet. I won’t give a recommendation for quantity as I haven’t come close to loading for such a light sub bullet. Sorry.
As for a sub load, I’d go heavier bullet. But if you insist on a 200gr bullet sub load. Try H110. As for a number, no one has really worked up a sub load for such a light bullet. I won’t give a recommendation for quantity as I haven’t come close to loading for such a light sub bullet. Sorry.
For hunting I'd choose the 200 gr FTX 338 Marlin Express, because its designed for a 700 fps lower muzzle velocity 1800 fps vs 2500 fps for the SST. And ya only lose 25 BC points .455 vs .430...all according to Hornady. With the SSTs minimum muzzle recommendation of 2500 fps it doesn't have much potential for expansion at distance. Ya run the 1800 fps min muzzle velocity you'd have a lot more yardage down range to have the bullet mushroom as designed.
I have some laying around but have not tested them. It would be up to you to test the distance you'd be comfortable with them making a clean kill.
I'd run em at 2600 fps in my rifle and then shoot some in media at 1800 fps and lower velicity to get an idea, where they stop preforming.
It would appear to be good for 300 yds, or so.
I use H 335...this works in 6.5 twists.
I have some laying around but have not tested them. It would be up to you to test the distance you'd be comfortable with them making a clean kill.
I'd run em at 2600 fps in my rifle and then shoot some in media at 1800 fps and lower velicity to get an idea, where they stop preforming.
It would appear to be good for 300 yds, or so.
I use H 335...this works in 6.5 twists.
I will be strictly plinking with the 200gr SST's and have no intention of hunting with them. (Range fodder shooting steel.)
Bottom line, I want a SAFE sub load that will NOT blow up in my face. I like the idea of a fast burning powder shooting suppressed and from what I have read, a faster burning powder is the way to go. (Please correct me if I am wrong here).
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Yes you want a fast burning powder to mitigate detonation and to ensure complete burn prior to the muzzle.
With 200 gr. projectiles you're going to have low loading density for subsonic with almost every powder in an 8.6 BLK case. This is one of the reasons Hornady created .338 ARC, with a smaller case capacity to prevent low density issues like you will have. In my opinion 200 gr. just isn't a suitable projectile for subsonic case fill volumes, you want something in the 280+ gr. minimum. I could be wrong though. I've just never seen a subsonic loading with that light of a projectile. You will probably have ignition issues.
I have heard of folks using Dacron/Polyester fiber to fill up low case volumes above the powder charge and ensure sufficient ignition, but you're on your own if that's the direction you choose to go.
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Speer makes a really cheap plinking bullet that is 272gr. @45-90 has a really good load that he put in these posts. Go back to page 16 I think. IMR4198 at 16gr with that bullet in 6.5 twist. I use h110 but I am around 15-16gr for my sub load. It appears that 16gr is at the top end for sub velocity so start lower and work up.
I have 8 pounds of Vihtavuori N32C Powder, which is pretty bulky and on the faster (burn) side. I would like to use that and find a Safe load to try.
Well if anyone is wondering if the 2024 batch of Faxon remmage barrels are still dogshit ... they are.
It's the worse barrel I've even owned, in over 20 years as a gun owner. It's pretty much worse than shooting a factory glock offhand at 50 yards. Even though my ES is single digit, I'll get 2 rounds in the same hole and then the next one will be 7 in higher. I have no muzzle device and there's no evidence of keyholing, it's just retarded.
I really want the 1/3tw to work because this build is meant to be a dedicated lightweight subsonic hunting rifle with the Maker REX 350 so I'm thinking about trying with a preferred defiance prefit ...
It's the worse barrel I've even owned, in over 20 years as a gun owner. It's pretty much worse than shooting a factory glock offhand at 50 yards. Even though my ES is single digit, I'll get 2 rounds in the same hole and then the next one will be 7 in higher. I have no muzzle device and there's no evidence of keyholing, it's just retarded.
I really want the 1/3tw to work because this build is meant to be a dedicated lightweight subsonic hunting rifle with the Maker REX 350 so I'm thinking about trying with a preferred defiance prefit ...
That’s a bummer, but reinforces my decision to bite the bullet on a Mos-Tek order.
Depends on the 8.6 Blk you're running, auto, bolt, twist rate, barrel condition.
The 3 twist should be limited to 900 fps with lead jacked bullets of any kind especially if running a suppressor.
The 5 and 6.5 twist are much more for giving.
The 8.6 was designed for heavy bullets, in sub mode. The 272 gainers are cheap an work for plinking.
Light bullets are basically for supers in the 8.6 Blk.
Bolts are better than autos for the light bullet subs, as many times they will not run the bolt carrier properly or at all, and have issues.
But if ya want to try Vit N32C or Tin Star with a 200 gr lead jacketed bullet...
Start at 11.0 gr and work up or down depending on barrel length, and a host of other variables. If a 3 twist, remove your muzzle device before testing anything different from proven loads for "your" barrel.
Rough rifling, plus super fast twist in many 3 twist put more stress on jacketed bullets, causing early bullet failure, so as to be dangerous.
So that one barrel, the load may be safe and the next barrel it may not be with the 3 twist.
I tested alot of bullets in 3 twist and 6.5 twist. And why I recommend the 6.5 twist...because it does not have the blow up problems with bullets.
My Faxon 3 twist AR has been discarded.
I run bolt gun 6.5 twist to get the versatility I want with any bullet, especially lead jacketed, cheap, shorter, more room for powder, and more supersonic energy on target.
For cheap sub shooting the smaller cases like the new 338 ARC, or 338 Spectre make alot of sense. Good case fill, excellent accuracy, consistent velocities.
I have been working with them too.
They are almost identical.
Here is a 338 Spectre chamber will almost chamber a factory 338 ARC factory brass when. 040" is trimmed off the neck.
1.7 gr H2O capacity increase for the ARC, but even that is not needed for most sub loads, except the 350 Maker is right around 900 fps in the Spectre, but the ARC has an 8 twist...which should be ok except for the 350 grs...maybe..., as Hornady is the only source for 8 twist subs...which we'll try in the 6.5 twist as soon as they are available.
Just loaded some 200 gr Marlin 338 express flex tip bullets in the 338 Spectre, for testing they should be over the 1800 fps minimum muzzle velocity to expand..to see if they offer a good cheap hunting solution for smaller cases.
The smaller cases in the AR 15 are a ton of fun, if ya handload.
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I have a McGowan 16" - 1 in 6.5" twist bolt action build. If you would please, give me a safe supersonic starting charge with Vihtavuori N32C Powder with a 200gr Hornady SST bullet. I will be using this as range fodder shooting steel in addition to sighting in a new build.
Same start as above with Vit N32C with the 200 gr bullet...
Approximately 11 grains close to sub to start and 18 gr to max. load.
Not the fastest in velocity but you should get some excellent accuracy near the top, if your barrel likes the bullet.
Approximately 11 grains close to sub to start and 18 gr to max. load.
Not the fastest in velocity but you should get some excellent accuracy near the top, if your barrel likes the bullet.
I was hoping Faxon would improve their 8.6 Blk barrels, as my early barrel was the absolute worst barrel I ever owned, or borescoped.
So Faxon earned the dogshit comments that unfortunately still applies.
So many who want to sincerely try the 8.6 Blk are disappointed...including me with my Faxon barrel, but at the time was the only game in town.
Now, others are now making 8.6 Blk barrels in 3 twist, 5 twist, & 6.5 twist.
If you want to stay with the 3 twist and 350 gr Maker for dedicated sub use, you should be able to do so with a good quality barrel.
Mos-Tek makes prefit Ramage style barrels for Remington 700. Choose the length and twist rate from 3, 5, & 6.5.
I'd probably go with the 5 twist for subs only, for better versatility... but it's your barrel...so you decide.
But 3 twist is harder to do with great results, and getting it constantly right, and keeping the rifling button from galling, tearing the base metal as it's pushed or pulled through the bore, using proprietary lubes and button grinds.
So one has to rely on reputation of the barrel maker, and hope for the best.
Not sure if you can use a R700, but Mos-tek has pre-mades occasionally.
If not, I think their backlog is still 6 months.
First off, many thanks to everyone here experimenting with 8.6 Blackout and sharing your insights.
I still think the cartridge has a lot of appeal for both subsonic and supersonic performance. However, the company that introduced it has zero interest in supporting 8.6 Blackout in the marketplace. Old news, I know, but here it is from the peerless leader’s own mouth:
I still think the cartridge has a lot of appeal for both subsonic and supersonic performance. However, the company that introduced it has zero interest in supporting 8.6 Blackout in the marketplace. Old news, I know, but here it is from the peerless leader’s own mouth:
For what its worth my Faxon FX7 8.6 BLK 16" barreled action has been flawless, had a September/October manufacturing date (can't remember which exactly). Maybe I just got lucky...
I just loaded up some Hornady 338 Marlin Express FTX 200 gr bullets for 6.5 twist 338 Spectre. They should be around 1800 fps.
To test them out soon as the weather permits.
So 1050 fps should be no problem.
I shoot 6.5 twist now in both subsonic guns, no problem with shooting any bullet as fast as either caliber will shoot it in super mode.
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My 8.6 loads are not improving with more questions than answers which is frustrating and interesting at the same time..
I took on 8.6 due to my love of suppressed 300 blackout and the desire to really force myself to better develop my meager reloading knowledge/skills. Add onto it that I still have a few working years left and I don't own property I can actually freely shoot on, I have to carefully plan all experiments. At least I do have an indoor 100 yard range nearby which allows me to collect all key learning... Oh, I enjoy pushing the limits of single rifle platform and, like the 300 blackout sub/sonic, and this 8.6 is no exception. Yes, the 8.6 purpose is for subs but my joy comes from max accuracy/energy as heavy (sub) as I can get and max accuracy/energy (speed) for as light as I can get on the same platform when I'm done with it...
Where I stand: (still just getting my 8.6 reload footing using cheaper 300 Grain sub and 210 Gain sonic)
(Have a Q-fix 12" bolt 8.6 for all below)
Subsonic: Sierra SMK 300 Grain
- A1680 / 17.1 grn / 2.740" COL - Average 1090 fps - STD ~14.0 / ExSpread ~35.0 (over about 50 rounds of latest/best)
- This leads me to a 1.5 MOA with about 5-10% of 2.5" fliers; STD I cannot improve on reliably anymore which is frustrating..
- All with same rifle fired annealed Starline brass with what I believe are all the proper resize/case prep steps in the proper order; individually weighted charge; added neck tension resized and individually weighted bullets of actual 300.0 each. Not applying any crimping for my bolt but it doesn't seem to need it anyway. Lands are still
(Q) Any feedback on what I may be missing to get sub-MOA with this load?
- Yea, I'm on the hot side of sub but it's holding together fine with spin rate.
- Working on getting 300 Grain Bergers to try versus Sierra's
- Will be shifting back to case seating depth tests - These Sierra's have about a max of 2.788" for me before hitting them so I will be working to get closer to them with those tests.
- Am using basic 8.6 Lee dies I first found with an older single stage Hornady press.
Sonic: Barnes 210 Grain TTSX BT
- A1680 / 30.9 grn / 2.675" COL - Average 1,900 fps - STD ~12 / ExSpread ~30.0 (over about 50 rounds of latest/best)
- This leads me to a 1.25 MOA with about 5-10% of 2" fliers
- All other same as above but Barnes have a 2.798" max COL before hitting the lands.
(Q) Any feedback on what I may be missing to get sub-MOA with this load?
- Barnes bullet weight spread is strangely much larger than the heavier Sierra bullets (ie. +/- 1.5 grains!) which seems like a lot to see but even with filtering down, not much changes in grouping for 100 yard tests.
- No other bullet options on table yet. Wish that Berger had more lower weight 338 options versus going with some misc expensive unknown brand options?
- Will also be shifting to case seating depth testing again but much closer to lands.
New Question arose? Any Feedback for this?
- 8.6 blackout. Forget subsonic vs sonic... What would it be most optimum load for this 8.6 period?
- ie. 300 grain at what load/speed or what between 200-350grains at what load charge that would perfectly fill the case and really rock with this 1:3 / .338 case platform at any speed) say using A1680, H110 or any other powders..?
I took on 8.6 due to my love of suppressed 300 blackout and the desire to really force myself to better develop my meager reloading knowledge/skills. Add onto it that I still have a few working years left and I don't own property I can actually freely shoot on, I have to carefully plan all experiments. At least I do have an indoor 100 yard range nearby which allows me to collect all key learning... Oh, I enjoy pushing the limits of single rifle platform and, like the 300 blackout sub/sonic, and this 8.6 is no exception. Yes, the 8.6 purpose is for subs but my joy comes from max accuracy/energy as heavy (sub) as I can get and max accuracy/energy (speed) for as light as I can get on the same platform when I'm done with it...
Where I stand: (still just getting my 8.6 reload footing using cheaper 300 Grain sub and 210 Gain sonic)
(Have a Q-fix 12" bolt 8.6 for all below)
Subsonic: Sierra SMK 300 Grain
- A1680 / 17.1 grn / 2.740" COL - Average 1090 fps - STD ~14.0 / ExSpread ~35.0 (over about 50 rounds of latest/best)
- This leads me to a 1.5 MOA with about 5-10% of 2.5" fliers; STD I cannot improve on reliably anymore which is frustrating..
- All with same rifle fired annealed Starline brass with what I believe are all the proper resize/case prep steps in the proper order; individually weighted charge; added neck tension resized and individually weighted bullets of actual 300.0 each. Not applying any crimping for my bolt but it doesn't seem to need it anyway. Lands are still
(Q) Any feedback on what I may be missing to get sub-MOA with this load?
- Yea, I'm on the hot side of sub but it's holding together fine with spin rate.
- Working on getting 300 Grain Bergers to try versus Sierra's
- Will be shifting back to case seating depth tests - These Sierra's have about a max of 2.788" for me before hitting them so I will be working to get closer to them with those tests.
- Am using basic 8.6 Lee dies I first found with an older single stage Hornady press.
Sonic: Barnes 210 Grain TTSX BT
- A1680 / 30.9 grn / 2.675" COL - Average 1,900 fps - STD ~12 / ExSpread ~30.0 (over about 50 rounds of latest/best)
- This leads me to a 1.25 MOA with about 5-10% of 2" fliers
- All other same as above but Barnes have a 2.798" max COL before hitting the lands.
(Q) Any feedback on what I may be missing to get sub-MOA with this load?
- Barnes bullet weight spread is strangely much larger than the heavier Sierra bullets (ie. +/- 1.5 grains!) which seems like a lot to see but even with filtering down, not much changes in grouping for 100 yard tests.
- No other bullet options on table yet. Wish that Berger had more lower weight 338 options versus going with some misc expensive unknown brand options?
- Will also be shifting to case seating depth testing again but much closer to lands.
New Question arose? Any Feedback for this?
- 8.6 blackout. Forget subsonic vs sonic... What would it be most optimum load for this 8.6 period?
- ie. 300 grain at what load/speed or what between 200-350grains at what load charge that would perfectly fill the case and really rock with this 1:3 / .338 case platform at any speed) say using A1680, H110 or any other powders..?
Well the main issue is the cartridge design (and maybe the twist): it's always been relatively easy to do accurate subsonic in a 300blk because the case is small relative to the bullet and its easy to achieve a good case fill/burn rate ratio. The 8.6 BLK case is kind of too big for subs and kind of too small for super and there's not a really optimal powder available. With 300BLK there was a ton of magnum pistol powders that would fill the case at least 75% - with the 8.6BLK, the same powders get 45-55% - that will absolutely impact your SD/ES
That said, I'm not sure I would use 1680 for an accurate long range subsonic load, your case capacity is barely 50% and your burn rate is not even 90% at 12in. It's a powder used to cycle a gas gun because it generates a lot of gas and its relatively slow burning (and dirty). I would say N120 is still superior in a gasser as its much cleaner.
1680 in my experience (in 300blk) likes to be run hot and compressed which does make it suitable for supersonic loads in a bolt gun but not subs.
I believe the best powder for subs in a bolt gun with the SMK or Berger 300 would be the N32c Tinstar but that might be hard to find if you don't have any on hand: it's been discontinued by VV due to the ukraine war but there might be some old stock floating around.
Other alternatives would be N105, N110, H110 and then maybe Alliant Red Dot, Green dot and even Blue dot might work better but I haven't seen too many reports on people using these although they seem to be a better fit for burn rate/case capacity - if you don't own Quickload it would be a bitch to work up a load without any published data out there.
As for the weird flyers ... I'm not experienced in this caliber but from what I've read, it could be the 3twist thing. A lot of experienced reloaders and shooters have reported consistency issues for long range subs out of the 3tw ... And I wouldn't trust your typical shill youtube influencers with their hand picked 300yards subsonic groups.
That said, I'm not sure I would use 1680 for an accurate long range subsonic load, your case capacity is barely 50% and your burn rate is not even 90% at 12in. It's a powder used to cycle a gas gun because it generates a lot of gas and its relatively slow burning (and dirty). I would say N120 is still superior in a gasser as its much cleaner.
1680 in my experience (in 300blk) likes to be run hot and compressed which does make it suitable for supersonic loads in a bolt gun but not subs.
I believe the best powder for subs in a bolt gun with the SMK or Berger 300 would be the N32c Tinstar but that might be hard to find if you don't have any on hand: it's been discontinued by VV due to the ukraine war but there might be some old stock floating around.
Other alternatives would be N105, N110, H110 and then maybe Alliant Red Dot, Green dot and even Blue dot might work better but I haven't seen too many reports on people using these although they seem to be a better fit for burn rate/case capacity - if you don't own Quickload it would be a bitch to work up a load without any published data out there.
As for the weird flyers ... I'm not experienced in this caliber but from what I've read, it could be the 3twist thing. A lot of experienced reloaders and shooters have reported consistency issues for long range subs out of the 3tw ... And I wouldn't trust your typical shill youtube influencers with their hand picked 300yards subsonic groups.
I’ve found unburned powder in my 8.6 cases a couple times w/ A1680 suppressed. May have to try N120.
Just to add to the already great replies, I was discussing 1680 and CFE BLK with Paul Maker for use with his subsonic loads, as I am about to get into subsonic load develpment as well, and he told me the following:
"CFE Black and 1680 works well for supersonic 8.6 blk but is not very accurate with subs. N110, H110, W296 and 11FS has been the most accurate powders. 14.5 gr of N110 is what once of my OEM's uses."
This was for the 350 Rex Subsonic expanding but based on what I've read and what Paul said, it's better to stick with the faster burning powders.
For super's I'm a firm believer in H335, you can search this thread for lots of good load data.
First the 3 twist is not for accuracy.... no one is shooting a 3 twist for accuracy.
I was a hunting design with subs up close where 2 to 3 MOA is plenty accurate, at 75 yds and under with the hunting bullets it was designed for.
The 8.6 Blk has too much case capacity with subs for super accuracy.
With all that capacity pressure is too low to burn most powders 100 % leaving larger than necessary velocity spreads.
Then for a high velocity it's basically not as good as the 338 Federal...although I get pretty close with a long barrel.
For short range accuracy 300 yds and under flat base bullets usually have an accuracy edge.
Bolt action and scrap the 3 twist, install a premium barrel with appropriate twist, would be the beginning of an accurate cartridge.
Match bullets get smaller groups...going for accuracy, ya have to be all in for accuracy...hunting is not so much.
Longer barrels for good powder burn, nothing on the end of the barrel, no muzzle breaks or suppressors.
Accuracy looks like a benchrest rifle, and cartridge to match, and 1/4" or less 5 shot groups will happen...like my 6 Dasher.
But you don't want that.
So you get an accuracy compromise.
Hunting doesn't require super accuracy.
The 8.6 Blk is not set up for accuracy.
For subs the smaller cases are better for accuracy like the 338 Spectre 6.5 twist or the new 338 ARC 8 twist should be good.
Because they are capable of complete powder burn in 16" with more powders, and case fill is high where it should be.
But they are not much for supers, because of the small case capacity....compromise again.
My accuracy really improved in 8.6 going from early AR 10 Faxon 3 twist to a Rem 700 with a McGowen 6.5 twist Rem Varmint contour 24" mounted in an aluminum chassis, that I chambered myself.
It has a muzzle brake, but no suppressor.
Now you will have a reasonably accurate rifle.
It's not set up for hunting, but LR shooting 300 gr Match Berger or Sierra at 2000 fps, or subsonic ...with accuracy...with hybrid cases.
Here the bulk of a 10 shot group inside 1" at 100 yds subsonic 300 gr Berger.
A ladder test shooting subs both 285 ELDM and 300 gr Match, shot at the same time... starting in tbe tape and going up as the velocity increases, trying to get the best velocity for both...they hang together here, until they get out of subsonic mode.
Or 200 gr Speer at 2600 fps, pulled one but 7 or 8 shots under 1".
Or 225 gr Speer lead 2407 fps.
Cheap lead bullets under one inch and better.
That's a 6.5 twist barrel versatility, shoots everything well even the 350 Maker Rex.
With a quality barrel, set up more like a target rifle.
But that's not what you want so then compromises are added and accuracy deteriorates.
And a good shot with good eyesight could do better...going blind in my right eye so I have to shoot left handed these days.
I was a hunting design with subs up close where 2 to 3 MOA is plenty accurate, at 75 yds and under with the hunting bullets it was designed for.
The 8.6 Blk has too much case capacity with subs for super accuracy.
With all that capacity pressure is too low to burn most powders 100 % leaving larger than necessary velocity spreads.
Then for a high velocity it's basically not as good as the 338 Federal...although I get pretty close with a long barrel.
For short range accuracy 300 yds and under flat base bullets usually have an accuracy edge.
Bolt action and scrap the 3 twist, install a premium barrel with appropriate twist, would be the beginning of an accurate cartridge.
Match bullets get smaller groups...going for accuracy, ya have to be all in for accuracy...hunting is not so much.
Longer barrels for good powder burn, nothing on the end of the barrel, no muzzle breaks or suppressors.
Accuracy looks like a benchrest rifle, and cartridge to match, and 1/4" or less 5 shot groups will happen...like my 6 Dasher.
But you don't want that.
So you get an accuracy compromise.
Hunting doesn't require super accuracy.
The 8.6 Blk is not set up for accuracy.
For subs the smaller cases are better for accuracy like the 338 Spectre 6.5 twist or the new 338 ARC 8 twist should be good.
Because they are capable of complete powder burn in 16" with more powders, and case fill is high where it should be.
But they are not much for supers, because of the small case capacity....compromise again.
My accuracy really improved in 8.6 going from early AR 10 Faxon 3 twist to a Rem 700 with a McGowen 6.5 twist Rem Varmint contour 24" mounted in an aluminum chassis, that I chambered myself.
It has a muzzle brake, but no suppressor.
Now you will have a reasonably accurate rifle.
It's not set up for hunting, but LR shooting 300 gr Match Berger or Sierra at 2000 fps, or subsonic ...with accuracy...with hybrid cases.
Here the bulk of a 10 shot group inside 1" at 100 yds subsonic 300 gr Berger.
A ladder test shooting subs both 285 ELDM and 300 gr Match, shot at the same time... starting in tbe tape and going up as the velocity increases, trying to get the best velocity for both...they hang together here, until they get out of subsonic mode.
Or 200 gr Speer at 2600 fps, pulled one but 7 or 8 shots under 1".
Or 225 gr Speer lead 2407 fps.
Cheap lead bullets under one inch and better.
That's a 6.5 twist barrel versatility, shoots everything well even the 350 Maker Rex.
With a quality barrel, set up more like a target rifle.
But that's not what you want so then compromises are added and accuracy deteriorates.
And a good shot with good eyesight could do better...going blind in my right eye so I have to shoot left handed these days.
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For subsonic, I wouldn’t focus on weighing brass or getting too deep in the weeds of details. I weighed everything, to include primers, to make sure everything was exactly within a .01 grain tolerance. The combination of bullets, powder and seating depth will have a greater effect. For me, Lapua Scenars had better accuracy and consistency than SMKs. My best sub loads used Lil Gun or N110. I was able to get groups around .5 MOA at 100 meters with a 1:3 Q barrel.
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