8.6 Blk reloading info
- Thread starter unclemoak
- Start date
Kinda like that...but I enjoy the challenge..and built a whole new rifle with 6.5 Twist barrel, in 8.6 ...but in a bolt gun, this go round.
Guaranteed to get there, ???...soon as the weather cooperates....stay tuned for some fast 8.6,... or one nasty stripper.
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Finnally got out to try out some high velocity 8.6 Blackout loads...in the new 6.5 twist barrel. They weren't as high as predicted...but not too bad either. Much better than the three twist...none came apart in mid flight or damaged the muzzle brake. No primers were blown, either.
Used two powders in ladder tests.
The results were 2480 fps for 200 gr, 2250 fps for 225 gr, 230 gr eldx 2200 fps, 285 gr 1873 fps, 300 gr Berger & Sierra 1808 fps
Powder #2 300 gr Berger 1943 fps, 300 gr Sierra MK , 1934 fps.
Used two powders in ladder tests.
The results were 2480 fps for 200 gr, 2250 fps for 225 gr, 230 gr eldx 2200 fps, 285 gr 1873 fps, 300 gr Berger & Sierra 1808 fps
Powder #2 300 gr Berger 1943 fps, 300 gr Sierra MK , 1934 fps.
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Ran the data for a 2480 fps 200 grain bullet (I assumed this was a Hornady SST) on a calculator. It’s comparable to a 20” .308 shooting 175 grain SMKs at around 2600 fps.
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Mos-Tek makes 3, 5, & 6.5 twist AR 10 barrels.Nice!
I cleaned my 8.6 (AR) yesterday. I started at 6:30am. I figured that it would be clean and I would be headed to the range by 10. Nope. I finally got the barrel cleaned to almost “borescope satisfaction” by 3:30PM. Carbon buildup (I blame that on shooting so much Gorilla ammo thru it and my A1680 reloads) was pretty bad. I don’t think it’s all out yet but it’s down to specsof carbon now. Once the carbon was mostly removed the copper showed up. That wasn’t too hard to get rid of but it wasn’t light. Then I worked on carbon fouling again. I let the various “remedies” soak an hour or so per instruction. I hit it with everything in my cleaning arsenal.
Borescoping the barrellet’s just say Faxon deserves all of the criticism it gets. The “substantial” gas port split a land about 2/3 land 1/3 groove.
Does anyone make a slower twist rate AR10 barrel?
I ordered a 6.5 twist blank from McGowen and chambered it myself. It took 3 months to get a 6.5 twist barrel and a .510 10 twist barrel.
They have a nice interior, like a barrel should. Not like the Faxon 3 twist barrel with rough torn rifling.
And high velocity bullets do not come apart to damage your muzzle devices or magneto speed chronograph.
Doing the high speed tests and tried just two powders with a variety of bullets.
The accuracy with the first powder looked excellent, for me, I have Macular Degeneration in the shooting eye so it's hard to see with bright sunlight...on overcast days just shoot the center of a distorted paper plate. Get eye injections to try to preserve the eyesight. My left eye has good sight, but shooting lefthand is awkward.
But, yesterday was able to put 3 or 4 in the same hole then move the impact up as powder increased.
IMO the 6.5 twist is a much better option for the 8.6 blackout and I already have a 3 twist, which is very limiting, in bullet choice and velocity it can run,...plus Faxon has bad rifling, on mine, and others. So far I can run any 338 lead bullet as fast as I can with no fear of bullet blow-ups. Which gets you into real killing power with much less cost. I shot some 2 liter jugs yesterday and the difference on impact was drastically different. Punch a hole or rip the jug to pieces in an explosive mist.
I know this post is quite old now, but I was also initially worried about the Gorilla 210 gr TSX ammo as I was seeing some significant extractor marks on my 8" gas gun back around the summer of 2022. Fast forward until today and I finally have a 16" barrel bolt gun that I shot through my Primal suppressor and measured the velocity for 7 shots with my Garmin Xero C1 as follows:
| Shot | Velocity | ||
| 1 | 2149.7 | 2140.80 | average |
| 2 | 2136.8 | 14.81 | std dev |
| 3 | 2166.4 | ||
| 4 | 2118.5 | ||
| 5 | 2133.2 | ||
| 6 | 2138.2 | ||
| 7 | 2142.8 |
I had called Gorilla in advance to see what the powder charge should be in these rounds and they told me 29.30 grains of whatever they were using. I pulled one just to confirm based on what I was seeing initially to double check and it was at 29.60 grains. Temp here in eastern PA today was probably around 45 F and elevation around 450', but the velocity was definitely nowhere near the 3100 you were initially seeing and I was worried about also seeing.
I also had loaded up some of my own 210 gr TSX rounds with 29.5 of AA1680 from the Q data and it gave me the following:
| Shot | Velocity | ||
| 1 | 2005.8 | 2031.96 | average |
| 2 | 2023.4 | 12.46 | std dev |
| 3 | 2034.7 | ||
| 4 | 2044.2 | ||
| 5 | 2032.1 | ||
| 6 | 2043.7 | ||
| 7 | 2034.6 | ||
| 8 | 2037.2 |
The first shot was the first round every out of that gun and without the suppressor, so that's what I'm chalking up to the lower velocity. COAL for both rounds were at 2.650".
I checked out the video ...if true, in the AR 15 platform?
There is no room with a 300 gr Berger, the bullet is down on the ogive for crimping.
So shorten the case back to where you can crimp it...the results is a tiny powder capacity for limited use, ... a sub load only option. But a better option than the current 8.6 for subs only, as the 8.6 Blackout has too much case capacity for subs.
But then, add the tiny capacity to weak bolts of the Grendel and a few tenths difference in powder charge or slight change in seating depth, will spike pressures beyond the bolt strength...and that could be a problem for handloaders. Hornady would most likely supply load data in the future, that would be strictly adhered to, so it may be a win for the sub only crowd.
They already have the 338 Spectre for the AR 15 platform...for subs
But it would be more successful if Hornady marketed it, as they hype the hell out of everything.
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Nothing new....Weatherby has long Freebore in their rifles since about 1950...to get the high velocity without the initial pressure spike...but there is still a pressure spike, delayed or slightly spread out for a fraction of a milli second.I was a bit premature with the "giving up post"
On another note, Shawn Carlock came out with his .338 Edge +P after my .338 Edge was delivered. If I remember right I could have a gunsmith use a +P reamer on it and make it a +P but it shoots fine and there is a barrel life cost associated with it. Here's Shawn's explanation for the stepped design that they are using and some history about +P chambering.
What if someone made a reamer with the +P stepped chambering for the 8.6BLK? It's supposed to reduce the initial, brass eating, pressure spike. I'm no gunsmith but physics is physics.
That's how Weatherby obtained its velocity records over the years.
Not to concerned about 8.6 blackout pressure spikes...I'm running 80,000 psi hybrid cases. But do not take them to that pressure.
Can not find the bullet ya want ...make your own, or modify existing bullets to fit your chamber. The all copper bullets are easy, to modify from weight to boattail, even the ogive for putting the bullet down the bore farther so you can add more powder.
It could be possible to reach 3000 fps in a 8.6 blackout...inquiring minds want to know...or...it gives retired machinist something to do.
I got 3760 fps in an AR 10 16" barrel with 50 gr copper 9mm hollow points, they grouped good but fade shed velocity very fast...a fun but ridiculous experiment of little value.
This will be more practical...and improve the 8.6 blk ...maybe?
Can not find the bullet ya want ...make your own, or modify existing bullets to fit your chamber. The all copper bullets are easy, to modify from weight to boattail, even the ogive for putting the bullet down the bore farther so you can add more powder.
It could be possible to reach 3000 fps in a 8.6 blackout...inquiring minds want to know...or...it gives retired machinist something to do.
I got 3760 fps in an AR 10 16" barrel with 50 gr copper 9mm hollow points, they grouped good but fade shed velocity very fast...a fun but ridiculous experiment of little value.
This will be more practical...and improve the 8.6 blk ...maybe?
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Before I even shot it, I lapped the 3 twist bore with silicon carbide valve grinding paste, available at automotive supply houses. In the Bridgeport, I milled a large V groove in home built aluminum vise jaw, over the Kurt hard jaw, and bolt it down.
A piece of leather belt over the face of the movable jaw.
Insert the new barrel and clamp it down.
Then machined a thick aluminum cup with a hole that slips over the cleaning rod and the cup is a snug fit on the barrel extension.
Tape the area where the rod stops before exiting the barrel with electrical tape.
slide the cup down to the tape.
Load the tight patch ...(it must be very tight) with the silicon carbide grinding compound. Tap in the bore with the leather glove on the hand.
Work it through the bore back and forth.
More at the chamber, and little at the muzzle. At to have a slight bore taper.
It will give your arms a workout, adjust the mill table to suit, your workout height.
Clean bore, check with bore scope, all lines parallel to bore, then a finish polish with Iosso paste, clean and done.
Helps the nasty Faxon 3 twist.
Just finished chambering a bolt gun on a 6.5 twist for the 8.6 Blk, with a nice barrel blank.
I also machine AR barrels from barrel blanks, that are not readily available from quality barrel suppliers.
A piece of leather belt over the face of the movable jaw.
Insert the new barrel and clamp it down.
Then machined a thick aluminum cup with a hole that slips over the cleaning rod and the cup is a snug fit on the barrel extension.
Tape the area where the rod stops before exiting the barrel with electrical tape.
slide the cup down to the tape.
Load the tight patch ...(it must be very tight) with the silicon carbide grinding compound. Tap in the bore with the leather glove on the hand.
Work it through the bore back and forth.
More at the chamber, and little at the muzzle. At to have a slight bore taper.
It will give your arms a workout, adjust the mill table to suit, your workout height.
Clean bore, check with bore scope, all lines parallel to bore, then a finish polish with Iosso paste, clean and done.
Helps the nasty Faxon 3 twist.
Just finished chambering a bolt gun on a 6.5 twist for the 8.6 Blk, with a nice barrel blank.
I also machine AR barrels from barrel blanks, that are not readily available from quality barrel suppliers.
For higher velocities ya need to go to slower powders.
W748, H335, & RL 17.
With copper bullets ya need .050" jump according to most manufacturers.
RL 17 33.7 gr max should get around 1700 fps at max pressure...all are a compressed load
W748 1680 fps 30.7 max
H335 1665 fps. At 29.7 grs max
WITH ONLY...2.825" COAL , 280 gr copper LRX bullet 1.864" length.
Nothing can be changed with out reworking up a load when you strive for max velocity, with heavy bullets, and small case capacities, as pressures Really spike.
Do not change seating depth as pressures spike tremendously with just .020" deeper into the small case...makes 4000 to 5000 psi difference. And all of the sudden you're way over max...weigh all charges .2 increase will get you into trouble...unless you're way down in the safely zone and can take a 5000 or more psi hit to the case, where most sub loads will be at.
The reason primers are blown and cases torn up, you're over pressure,.. Stop.
Those are informational loads and to be worked up to slowly...if used at all.
The 3 twist looses slightly more velocity because there is more energy expanded to the bullet's rotation and a bit less left for forward velicity.
The reason I went to the 6.5 twist and a bolt gun, to utilize the hybrid 80,000 psi cases incase of a 5000 psi pressure spike will not cause any damage, if I seat one .030" too deep or get .2 grain powder extra in the case. And can run all the loads to magnum pressures of 65,000 psi or slightly more...in a bolt gun with 6.5 twist, you can use cheap lead bullets, 200 grs at 2480 fps on the first powders tried...more experiments needed, I think it will reach much higher velocities.
Can not do lead bullets very fast in a 3 twist max 1400 to 1600 fps most will blow up soon as they leave the barrel, some less.
Also maching some hornady GMX copper bullets to 152 gr to see what they will do, they are machined to fit my chamber with .050" jump.
Yeah, a bit extreme...but in the end I will know what the 8.6 Blackout is capable of... even if its not available from manufacturers, I will make it myself...to find out.
There is no scientific evidence that a fast twist develops more killing power. A bullet spins only once in 3 inches or once in 10 inches, makes little difference.<Edit> 18" barrel makes no sense with this round. If I change barrels I'd think about 1:5 or 1:6.5 twist, and the heavy, Xray, barrel. But I do like the 3 twist, just not the limited bullet selection. 6 months or better lead time
Also... looking at the Berger stability calculator, the LRX is stable at subsonic speeds at 8 twist. I guess the lower rotation speed would take away some of the effect of the bullets impact. And... same old problem, I don't know if the LRX will expand at subsonic impact velocities. Spinning fast like what I get with a 3 twist barrel is probably going to give good terminal ballistics performance.
But bullet high velocity along with bullet mushroom, and fragmentation, make big wounds, hitting bone and blowing it into tiny pieces, cause the bone to become a projectile.
Every wound channel and wound in flesh and bone is different, no two are alike. It ain't consistent like ballistics gel.. ya can't poke your finger into the side of a deer, elk, or bear.
A bullet stops spinning, or begins to tumble, curves off path, resulting in different wounding properties or lack there of.
An 8 twist will stablize most of the bullets, for this caliber. I went with the 6.5 because there is no downside. I can run cheap lead bullets, at high velocities.
My AR has a 16" barrel. My bolt gun is 24" barrel for high velocity with all bullets.
I'm machining my own copper bullets to fit my chamber, and expect to get to 2900 fps...maybe. This bolt gun will shoot subs but is primarily a high velocity endevor. I shot a 2 liter jug with 300 gr match bullets at 1943 fps...it just punched a .338 hole through and water slowly leaked out.
Did the same with a cheap lead 200 gr Speer at 2500 fps and the 2 liter just exploded.
IMO bolt guns with good 20" barrels really improve the high velocity killing power, and accuracy of the cartridge using conventional lead bullets in 6.5 twist, and have ya covered when using subs...very versatile. Your gun build it your way. Just sharing what I've learned messing with making this 8.6 work for me.
The 1.864" IS the actual length of the bullet listed.
Not the cartridge.
Seating bullets to jam can cause huge pressure spikes like 10,000 psi especially with copper.
Should always know where the lands are with relationships to your cartridge overall length.
SA have been good adjustable gas blocks, for me.
Eample, count the clicks down from standard or sub velocity to high pressure loads..on 308 its 7 clicks down to run 200 gr SMK at 2674 fps in an 18" barreled AR 10, run the same pressure as the bolt gun. Then 7 clicks open for standard 168 gr ammo.
ARs are capable of excellent accuracy with good barrels .5" 5 shot groups are common.
Add a sticky backed fiber strip, available at craft stores, to the shell deflector of the AR to eliminate dented cases and case mouths.
Keep working on it... imr4350, is a bit too slow.
Some that "might" get 1500 fps with some accuracy...try
Max loads work up with 280 gr at 2.825"
H322 28 GR
H335 29.7 GR
BC-L2 32 GR
H 4895 29.7 GR
IMR 4198 24.8 GR
8208 XBR 29.1 GR
IMR 3031 29.1 GR
AA 2495 30.8 GR
AA 2520 31.1 GR
W 748 30.8 GR
Information to carefully observe, study, and play with, at your own risk..work up carefully...
Something in this group should improve your end results.
Have fun.
Some that "might" get 1500 fps with some accuracy...try
Max loads work up with 280 gr at 2.825"
H322 28 GR
H335 29.7 GR
BC-L2 32 GR
H 4895 29.7 GR
IMR 4198 24.8 GR
8208 XBR 29.1 GR
IMR 3031 29.1 GR
AA 2495 30.8 GR
AA 2520 31.1 GR
W 748 30.8 GR
Information to carefully observe, study, and play with, at your own risk..work up carefully...
Something in this group should improve your end results.
Have fun.
If Hornady is going to make 8.6 ARC on the Grendel case it'll basically be 338 Spectre/338 Razorback with the 6.5 vs 6.8 bolt face, no? Could be cool for the guys who are trying to collect the whole set of ARC cartridges, haha.
And I definitely think you're right that it'll be subs only at AR15 mag length. I think Hornady has seen the disadvantages of the 1:3 twist and is divorcing themselves from it. The market wants to shoot .338 projectiles out of a gun, but 8.6BO in its current form just seems to have too many warts.
Been watching since the beginning. I think it's a neat niche gun. With that said I want one haha.
View attachment 8353404
I really like that lower@unclemoak Gorgeous rifle set up.
It's done a hurting on stacks of pigs.
Now I really need to find a lighter cast bullet, the 315gr cast I have been shooting have been flying straight and not exploding at up to 1200fps out of my bolt action. If I had some of those steel headed cases I would try to push them harder. So where did you get them from?
Greg
I bought the last 300 hybrid cases in stock...they will arrive in a few days. I already converted 100 of them. They were on sale! And sold out, quickly. Don't know if any will come back in stock, this was at American Reloading.
The military is supposed to be using them, if the war effort subsides they should be plentiful and cheap everywhere.
They require some work, like neck turning, and annealing. But give you a safety margin if ya don't over do it. And have a bit more case capacity.
I pushed the cheap jacked Speer bullet to 1600 fps in my 3 twist AR 10,16" ..but that depends on how rough your 3 twist is..if from Faxon...I had to lapp mine with silicon carbide lapping compound.
I used 19.7 gr 1680 2.570" OAL 200 gr lead jacketed Speer hot core...really cheap. And they didn't explode, plus fairly accurate. Fired in AR 10 3 twist.
I shoot this bullet to 2480 fps in the 6.5 twist bolt gun, hybrid cases and a different powder.
This might be the best bullet for this cartridge in supersonic endeavors, especially the 6.5 twist where you can go all out. I have machined some copper bullets about 153 grs, expecting some good velocities on these, as they are machined to fit my chamber giving maximum powder capacity. I can make them very light incase I want to go to 3000 fps in the 8.6 bolt gun... more fun than serious. Stay tunned...been sickly and the weather is nasty.
Here is a picture of the two bullets seated the machined 153 gr copper longer then 2500 fps 200 gr Speer, for 6.5 twist barrels. There is 45.9 grs of powder under the copper 153 hybrid case. That is about max for that powder... load more and chronograph in a few days. Kind of a mad scientist on this high velocity tour for the 8. 6 Blackout.
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I have some loaded as well as supers, for my 6.5 twist.
But came down with a bad case of shingles, so it will be awhile before I return to test them.
I did shoot ladder test with super sonic and the 6.5 twist was much more accurate than the 3 twist, before getting sick. In fact some excellent super groups.
But, that may not be a fair comparison.
The 3 twist is a Faxon barrel with its inferior torn rifling...and the 6.5 Twist is a custom ordered barrel took 3 months to get, as a barrel blank...that needed to be chambered and threaded, it has a nice interior.
I see no need for the radical 3 twist, and I own one,...and that was enough.
Get the 45-90...life is too short. You have the stuff....so fulfill the dream.
Its shoots 500 gr cast and 350 gr Berrys heavy plated rated at 1900 fps. subsonic or super your choice.
I use 45-70 and 45-90 brass. Some 45-70 for subs.
I use the lathe & collets to drill deep hollow points in Berrys bullets .200 deep hp 10.3 gr of Red Dot for 864 fps, quiet small game load, little recoil. Or 10.5 red dot 250" deep hp for 1113 fps. 10.3 red dot on a 350 gr no hollow point 952 fps.
Or have cast 500 gr subs for heavy game or Hornady Sub X 410 gr super or sub.
Recoil gets stout when 500 grs are 1800 fps or over, but always fun to shoot a few.
Before I got sick a few weeks ago I fired 100 rds of 45-90, without stopping, the barrel was so hot I had to hold low on the walnut stock to escape the heat from burning my fingers...and let the barrel cool 15 minutes before putting in the gun case and head home...my other rifle was the 8.6 blackout 6.5 twist, out for testing...
Its shoots 500 gr cast and 350 gr Berrys heavy plated rated at 1900 fps. subsonic or super your choice.
I use 45-70 and 45-90 brass. Some 45-70 for subs.
I use the lathe & collets to drill deep hollow points in Berrys bullets .200 deep hp 10.3 gr of Red Dot for 864 fps, quiet small game load, little recoil. Or 10.5 red dot 250" deep hp for 1113 fps. 10.3 red dot on a 350 gr no hollow point 952 fps.
Or have cast 500 gr subs for heavy game or Hornady Sub X 410 gr super or sub.
Recoil gets stout when 500 grs are 1800 fps or over, but always fun to shoot a few.
Before I got sick a few weeks ago I fired 100 rds of 45-90, without stopping, the barrel was so hot I had to hold low on the walnut stock to escape the heat from burning my fingers...and let the barrel cool 15 minutes before putting in the gun case and head home...my other rifle was the 8.6 blackout 6.5 twist, out for testing...
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So after letting this sit for a while, I decided to pick it back up again. Thanks to all that lent their expertise. I did end up getting down into the transition below the neck a bit. That made the loads fit the gauge even better. It also made them fit in my rifle and fire correctly. I made a collet to fit my lathe to make the process faster. Thank you 45-90 for your post on that. I worked up a couple different loads for testing. After figuring out my Cauldwell chrono was junk, I picked up a Garmin Zero C1 Pro. This thing is fantastic and easy to use. Here is what I came up with and the results.
Both these loads are with Hornaday 285 ELD-M bullets, CCI 200 primers, and mixed brass. COAL 2.76 on both loads. The groups were decent. Sorry no pictures. I am working on some loads with Hornaday 270 ELD-X bullets. Will report my results when I test.
1st test round 16gn A-1680:
1. 1010.3
2. 1028.2
3. 1052.0
4. 1049.1
5. 1040.2
2nd test round 17gn A-1680
1. 1097.8
2. 1093.5
3. 1115.1
4. 1083.6
5. 1083.2
Not to derail the thread, but an '86 in 45-90 is a bucket list rifle for me, and the short list at that.
Yep, gotta have an Win 1886 short rifle in 45-90 ...and Real SAA in 45 Colt caliber, made by Colt. A fun way to hit the mountain trails.
It’d be nice if #2 turns out to be consistent. I looked over my older notes and found that my consistent loads all used SRP brass. I’m going to try going back to SRP until I find LRP brass loads that work.
Gotta keep trying, the SR primered cases may help...along with powders that give good fill, by volume.
Much of the accuracy problems are in the Faxon barrels, and a quality barrel replacement is the answer for better accuracy with a slower twist.
But, they should be accurate enough for short range.
Shot some 300 Bergers at 2 liter jugs...they were very unimpressive as to killing power.
Even at 1943 fps they just punched a .33" hole on the 2 liter...like shooting it with a Bow using a point target arrow...the liquid slowly drained out.
200 gr lead at 2480 fps exploded the 2 liter in the 6.5 twist.
I'm going for the highest velocities instead of subs this go round...using mostly lead bullets without worry of them exploding in the muzzle brake, with the 6.5 twist.
Will shoot a few subs also.
The 300 gr Bergers are for long range target, only, IMO.
They just punch a small caliber hole even way above sub speeds...look like they would be slow kills, even on squirrels.
Recovering from being sick...will be back out testing the high velocity loads in a few days.
Much of the accuracy problems are in the Faxon barrels, and a quality barrel replacement is the answer for better accuracy with a slower twist.
But, they should be accurate enough for short range.
Shot some 300 Bergers at 2 liter jugs...they were very unimpressive as to killing power.
Even at 1943 fps they just punched a .33" hole on the 2 liter...like shooting it with a Bow using a point target arrow...the liquid slowly drained out.
200 gr lead at 2480 fps exploded the 2 liter in the 6.5 twist.
I'm going for the highest velocities instead of subs this go round...using mostly lead bullets without worry of them exploding in the muzzle brake, with the 6.5 twist.
Will shoot a few subs also.
The 300 gr Bergers are for long range target, only, IMO.
They just punch a small caliber hole even way above sub speeds...look like they would be slow kills, even on squirrels.
Recovering from being sick...will be back out testing the high velocity loads in a few days.
Well got the super sonic test done today for the 8.6 Blackout with a 6.5 twist.
Top velocity for the cheap Speer 200 gr lead bullets was 2604 fps with H335.
AA 2495 =2451 fps
CFE223= 2572 fps
IMR 4198 =2433 fps
2000 MR =2494 fps 4.3 S/D
Machined copper Hornady 225 gr GMX cut down in lathe collet to 154 gr were fired with H335 and reached 2788 fps.
Caught one in water jugs it mushroomed up very nicely.
Shot a few 300 gr Subs in both Sierra with 1680 and 300 gr Berger with imr 4198 in the 6.5 twist the Sierra strung out vertically...the Berger was round 5 into 1.1"
All in all a successful day. The 6.5 twist is totally versatile as I suspected it would be. And the 8.6 Blackout comes close to the 338 Fredral, with supers, for some real killing power.
There was snow still heavy on the road and fallen trees across the road. Had to turn back to a bit lower elevation.
Top velocity for the cheap Speer 200 gr lead bullets was 2604 fps with H335.
AA 2495 =2451 fps
CFE223= 2572 fps
IMR 4198 =2433 fps
2000 MR =2494 fps 4.3 S/D
Machined copper Hornady 225 gr GMX cut down in lathe collet to 154 gr were fired with H335 and reached 2788 fps.
Caught one in water jugs it mushroomed up very nicely.
Shot a few 300 gr Subs in both Sierra with 1680 and 300 gr Berger with imr 4198 in the 6.5 twist the Sierra strung out vertically...the Berger was round 5 into 1.1"
All in all a successful day. The 6.5 twist is totally versatile as I suspected it would be. And the 8.6 Blackout comes close to the 338 Fredral, with supers, for some real killing power.
There was snow still heavy on the road and fallen trees across the road. Had to turn back to a bit lower elevation.
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Using Reloaded 15 with subsonic 300gr pills.
Has anyone tried RL 15 with 300gr subs out of an 8inch barrel? Using gordons reloading tool it looks promising. My goal is to try and get a higher fill volume in the case primarily so overthrows are more noticeable. With Accurate 1680 an overthrow is very easy (dont ask me how I know).
Basically looking for any powder that can get me north of 65% case fill that will work well with subsonic 8.6blk reloads.
I would appreciate any feedback.
Regards
Has anyone tried RL 15 with 300gr subs out of an 8inch barrel? Using gordons reloading tool it looks promising. My goal is to try and get a higher fill volume in the case primarily so overthrows are more noticeable. With Accurate 1680 an overthrow is very easy (dont ask me how I know).
Basically looking for any powder that can get me north of 65% case fill that will work well with subsonic 8.6blk reloads.
I would appreciate any feedback.
Regards
I have been working on super sonic loads with only a little on Subs with the AR platform 3 twist Faxon mostly a disappointment.
I chambered a bolt gun, trued the 700 action, and installed a 24" 6.5 twist. So supersonic is fast, tried a few left over 300 gr subs one load of imr 4198 showed better accuracy, then AA1680, which had vertical stringing and high S/D s.
I have used Trailboss in 308 & 50BMG sub loads, but do not have much left.
Another guy used Tin Star for his 8.6 build but both of these bulky powders are unavailable.
Getting the velocity SD low as possible are key if ya want to extend the range of the subsonic 8.6 loads. Close range hunting at big game it's not as important.
May try some Trail Boss in the 6.5 twist out of curiosity. Also could change to SR cases or use pistol primers to get S/D down, on sub loads. Lots of experimenting to do.
I chambered a bolt gun, trued the 700 action, and installed a 24" 6.5 twist. So supersonic is fast, tried a few left over 300 gr subs one load of imr 4198 showed better accuracy, then AA1680, which had vertical stringing and high S/D s.
I have used Trailboss in 308 & 50BMG sub loads, but do not have much left.
Another guy used Tin Star for his 8.6 build but both of these bulky powders are unavailable.
Getting the velocity SD low as possible are key if ya want to extend the range of the subsonic 8.6 loads. Close range hunting at big game it's not as important.
May try some Trail Boss in the 6.5 twist out of curiosity. Also could change to SR cases or use pistol primers to get S/D down, on sub loads. Lots of experimenting to do.
I've been looking at it seriously tonight.
You want high bulk density and 100% burn a tough combination with this case capacity.
10.2 gr of Trail Boss on a 300 gr Sierra MK bullet at abiut 2.760" to 2.8" should work.
Have to play with the charge to get the velocity.
Also Clay's is bulky and 100% burned about 10.0 gr for the same 300 gr bullet, not as good bulk wise as Trail Boss, though.
Get too slow of a propellant to fill up the case..but not all the powder is burned, usually causing velocity variations.
With a good barrel one should find something acceptable....at least able to satisfy your needs for the cartridge.
These are for bolt guns, my not produce enough gas to operate a gas gun.
You want high bulk density and 100% burn a tough combination with this case capacity.
10.2 gr of Trail Boss on a 300 gr Sierra MK bullet at abiut 2.760" to 2.8" should work.
Have to play with the charge to get the velocity.
Also Clay's is bulky and 100% burned about 10.0 gr for the same 300 gr bullet, not as good bulk wise as Trail Boss, though.
Get too slow of a propellant to fill up the case..but not all the powder is burned, usually causing velocity variations.
With a good barrel one should find something acceptable....at least able to satisfy your needs for the cartridge.
These are for bolt guns, my not produce enough gas to operate a gas gun.
Installed a more expensive scope on the 8.6 to help me see the target.
Shot the subs today to see how they do in the 6.5 Twist McGowen barrel, I chambered and installed on a trued Remington 700 which I also did in my shop.
Snow still on the ground and fallen trees everywhere, but I made it out to shoot .
Tried some Trail Boss and Red Dot, with LR and LP primers, to see the result.
With Red Dot there was little difference in velocity, but better accuracy and better S/D with the LR primers.
But Trail Boss was shocking... about 250 fos difference, 741fps to 482 fps LR vs LP primer...had to stop the test to make sure the bullet exited the barrel, it did but that velocity is too low to continue with the pistol primers.
The remaining 4 Trail Boss loads st 700 fps went into about .8" low off the plate into the cardboard backer, but this is not the powder, S/D too high, even though the load density is great. The 6.5 twist stabilized the 300 SMK at 700 fps. Plus cheap 200 gr Speer lead bullets to 2600 fps.
Much more versatile than my inaccurate Faxon 3 twist, which would limit lead bullets to about 1200 fps as they came apart if shot much faster.
Red Dot had a good showing lower S/D and 5 shot groups hit .4"
Had AR 10 loads, already loaded 300 gr Sierra MK with AA1680 15.8 gr. S/ D was a bit high but it put 8 shots into .5" with the 6.5 twist bolt gun, the AR 10 Faxon 3 twist was about 2" plus for 5 shots, and this was its best load for the 300 gr SMK.
A good day out shooting.
Shot the subs today to see how they do in the 6.5 Twist McGowen barrel, I chambered and installed on a trued Remington 700 which I also did in my shop.
Snow still on the ground and fallen trees everywhere, but I made it out to shoot .
Tried some Trail Boss and Red Dot, with LR and LP primers, to see the result.
With Red Dot there was little difference in velocity, but better accuracy and better S/D with the LR primers.
But Trail Boss was shocking... about 250 fos difference, 741fps to 482 fps LR vs LP primer...had to stop the test to make sure the bullet exited the barrel, it did but that velocity is too low to continue with the pistol primers.
The remaining 4 Trail Boss loads st 700 fps went into about .8" low off the plate into the cardboard backer, but this is not the powder, S/D too high, even though the load density is great. The 6.5 twist stabilized the 300 SMK at 700 fps. Plus cheap 200 gr Speer lead bullets to 2600 fps.
Much more versatile than my inaccurate Faxon 3 twist, which would limit lead bullets to about 1200 fps as they came apart if shot much faster.
Red Dot had a good showing lower S/D and 5 shot groups hit .4"
Had AR 10 loads, already loaded 300 gr Sierra MK with AA1680 15.8 gr. S/ D was a bit high but it put 8 shots into .5" with the 6.5 twist bolt gun, the AR 10 Faxon 3 twist was about 2" plus for 5 shots, and this was its best load for the 300 gr SMK.
A good day out shooting.
Attachments
I’ve got a pile of Maker 350gr bullets and Hornady CX. Hoping CFEBLK works okay in both.
Noticed some new Alpha Munitions 8.6 Blackout cases, called OCD, as they optimized for high pressure and have SR primers. Available at Mile High Shooters for $125 per hundred.
They should give you a one extra protection with your normal loads....but allow for a bit extra performance with out going overboard.
The 308 OCD cases were taken to 100,000 psi in a Bat action in a test, video on Ultimate Reloader, Do not do this at home , 308 Win completing with the 300 WM. Titled show.
For those interested....check it out...I may try the Alpha 8.6 OCD brass myself, later.
They should give you a one extra protection with your normal loads....but allow for a bit extra performance with out going overboard.
The 308 OCD cases were taken to 100,000 psi in a Bat action in a test, video on Ultimate Reloader, Do not do this at home , 308 Win completing with the 300 WM. Titled show.
For those interested....check it out...I may try the Alpha 8.6 OCD brass myself, later.
Since I'm running a 6.5 twist,...now... been doing alot of high velocity testing, got a bunch of bullets coming to test. Getting good sub groups already with 300 gr match bullets. Don't plan on hunting with the 8.6 in that capacity. I running reformed .277 Fury hybrid cases almost exclusively in the 8.6 Blackout finishing another 100.
Just finished building my 8.6. 12" Faxon 1-3 twist barrel. Porq chop suppressor . Gorilla case, Remington large rifle primer, 14.7 gr Accurate 1680, bullets are 300 grain seconds that came from Midway. Pretty sure they are Sierra Match King. 934 ft sec average. Bolt cycles and locks on last open on last round. Going to go up a few grains and see if I can get between 1025 - 1050 ft sec.
OAL?
BTW - I've been warned about increasing by "grain" amounts and ushered to only increase loads by fractions of grains due to how quick pressures spike in this particular case.
if you're looking to achieve ~10% velocity increase I was advised into .5gr max. increment increases (not sure if that applies to subs and supers or just one of those)
I looked at the Alpha brass in 8.6 blackout and considered getting some because its good brass, I use it in 6 Dasher
It will handle high pressures, probably not needed in most subs, but good consistency might help with vertical on the longer range targets, with lower extreme velocity variations.
I'm doing good with the 6.5 twist with 300 gr subs, with hybrid csses, but wonder if Alpha brass could make that even better.
So I'm gonna order some. It's been selling fast as some were $118 per hundred. Look for free shipping, promo codes.
After using the 6.5 twist and getting almost 338 Federal velocities with cheap lead bullets and over 3000 ft/ lbs of energy, plus excellent accuracy from the sub 300 gr loads, I'll probably never use my 3 twist barrel again, as it's so limiting and does not provide the accuracy of the 6.5 twist barrel.
Got a bunch of High velocity bullets coming for hunting Barns 160 gr to 250 gr to see what velocities are possible with the 8.6 blackout.
Plan to turn the old 3 twist 8.6 blackout AR 10 into an AR 10 338 RCM 18". Ordered the chamber reamer, gauges, barrel, have the modified bolt and upper, with dies, and brass to modify on the way. It always takes a few months to acquire all the stuff.
Were the BR 4s hard to seat?
The primers may not be seating properly.
If so run Remington 7 1/2 primers in your Alpha brass, as I do in the 6 Dasher...they will seat normally as the cup has a bevel to start and not square like the CCI and most others.
The Alpha brass has tight primer pockets, even with my 110 gr 3085 fps Dasher loads they will take awhile to loosen up.... stay with the Rem 7 1/2, they fire every time and produce small groups and are for high pressures, with their thicker cups, but no problem seating them, and they all go bang.
I did notice they were harder to seat than what I’m used to. I’ll have to give the Remington’s a try.
My OAL is 2.755
I've loaded up 5 each of 14.8g 14.9g and 15g. Next range trip will be in a couple weeks. I'll post my results then.
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