8.6 Blk reloading info

[45-90]

I’m doing 12.5in 1/6.5 twist on a ARC CDG action with a cone breech so I can use AW mags.
Primary loads will be the 350 REX but kinda looking for a cheap-ish ballistic equivalent for 300-400 long range subsonic steel shooting.
Won’t be super high volume shooting unless I can find a powder as good as N32c for consistent long range subs.
Will be using LRP with Alpha brass. Most likely Fed 210m

There are not too many cheap 338 bullets.
The 272 gr was cheap, but I just use them for plinking, along with Speer 338 bullets.
The 250 gr Game king BT may provide similar ballistics but less weight for ringing steel... it was fairly accurate...and a bit cheaper.
For lead casting I'd go with 315 gr NOE, its designed for subs with high tech coatings, I have not used them in the 8.6 but this one is designed for the Spectre 6.5 twist.
I personally use 300 gr SMK or 300 Berger for any long range shooting, each has a different powder preference in my 6.5 Twist barrel. Try to find free shipping days, and discounts to help lower your shooting costs.
.

 

[st1650]

There are not too many cheap 338 bullets.
The 272 gr was cheap, but I just use them for plinking, along with Speer 338 bullets.
The 250 gr Game king BT may provide similar ballistics but less weight for ringing steel... it was fairly accurate...and a bit cheaper.
For lead casting I'd go with 315 gr NOE, its designed for subs with high tech coatings, I have not used them in the 8.6 but this one is designed for the Spectre 6.5 twist.
I personally use 300 gr SMK or 300 Berger for any long range shooting, each has a different powder preference in my 6.5 Twist barrel. Try to find free shipping days, and discounts to help lower your shooting costs.
.

I've located some cheap-ish 300 Lapua Scenar locally, so that'll do for now ... I always want to maximize the case capacity so the longer, the better.
250Gr would probably work really well with Trailboss but I'm getting low on stock and I'm not sure if they've re-started producing it yet.
Seems like Hornady won't release the 307 SubX as a bullet component this year.

 

[st1650]

Has anyone tried N320 for the 350Rex ?
Also does the 1/3 tw require a higher load charge for same velocity than 1/6 ? Could explain why some people are hitting pressure earlier ?

 

[SaltyDog89]

New to 8.6 Blk and jumping into it with a fix 12" Bolt. Accuracy is coming but still working up general loads so safety is also kind of top of mind here initially. I'm also new to anything .338 coming from a .308 & 300 Blk personal reference, let alone the1:3 twist.

Sonic: Barnes 210 grain TTSX seemed like a good start for me:
all purchased brass: Gorilla & Starline 1st shot use (currently ignoring any other case prep details)

Two of my loads to note here :
- A1680 : 31.00 grn : COL 2.700 pushes 1914 fps (11.8 std)
- H110 : 29.00 grn : COL 2.700 pushed 2026 fps (26.2 std)
It looks like I pushed too hard with the H110 which made me really nervous but the sweet max spot seems to be better using A1680 with 31.00 grains for this. Any general safety comments on either but the A1680 31.00 grain feels like the way to go here?
Secondly, I seem to have about .09" before the bullet touches the lands with a 2.700" COL. Does anyone have a good feel for how Q-FIX bolts like being seated COL wise for this round?

 

[MSBRPT]

Secondly, I seem to have about .09" before the bullet touches the lands with a 2.700" COL. Does anyone have a good feel for how Q-FIX bolts like being seated COL wise for this round?

It’s going to depend on the projectile and the barrel. I’ve loaded a handful of different projectiles for various cartridges for the fix. For 8.6, my 1:6.5 twist barrel lands are much closer to the chamber than the 1:3. I had to seat bullets further into the case. A load that worked in my 1:3 couldn’t work in the 1:6.5. Chambering a round was tight, when I went to extract the round the lands were pulling the projectile. For the 1:3, I’ve had 2.8 COL work best for one projectile, 2.7 for another and 2.560” for the 350 maker in my barrel. Rule of thumb from what I’ve gathered for copper monolithics is that they prefer to jump to the lands. Going back to my 1:6.5 twist barrel, the Discreet Ballistics 280 grain projectile shot a group less than or right at .5” seated to 2.475” COL. I can’t remember what the jump distance was to the lands off the top of my head. I just remember thinking the load wasn’t going to perform well with such a significant jump. Most of my 8.6 experience has been subsonic. I’ve just recently started shooting supers.

 

[db2000]

Hey JM. Regarding using A1680 with the Barnes 225g TTSX. You said it was hot at 35.8gr. What length barrel were you using? I have a 16” Faxon Remage steel barrel. I know this is 2+ years ago. And it seems to me that was a typo on Faxon/K. Britingham sheet they had put together. If you remember let me know what barrel length. I’m starting at 25.5g.
Sounds like this is too low. Let me know your thoughts if you get a minute. Thanks
T

Not 225 but 210. Pressure signs high at 31.0 of A1680.

2/20/24
48F 42% 30.38in

Seekins and 10.5” Mos-Tek 1:6.5
Garmin Xero

Barnes 210 GR TSX BT solid
A1680
Q brass x 2
FGMM 210M
BTO 2.6100
COAL 2.670 (not 2.0670)
COL 1.6775
29.5 1762, 1773, 1757
30.0 1837, 1799, 1794
30.5 1920, 1817, 1834 1” @ 100

 

[SaltyDog89]

It’s going to depend on the projectile and the barrel. I’ve loaded a handful of different projectiles for various cartridges for the fix. For 8.6, my 1:6.5 twist barrel lands are much closer to the chamber than the 1:3. I had to seat bullets further into the case. A load that worked in my 1:3 couldn’t work in the 1:6.5. Chambering a round was tight, when I went to extract the round the lands were pulling the projectile. For the 1:3, I’ve had 2.8 COL work best for one projectile, 2.7 for another and 2.560” for the 350 maker in my barrel. Rule of thumb from what I’ve gathered for copper monolithics is that they prefer to jump to the lands. Going back to my 1:6.5 twist barrel, the Discreet Ballistics 280 grain projectile shot a group less than or right at .5” seated to 2.475” COL. I can’t remember what the jump distance was to the lands off the top of my head. I just remember thinking the load wasn’t going to perform well with such a significant jump. Most of my 8.6 experience has been subsonic. I’ve just recently started shooting supers.

Appreciate this feedback. I started with Supers since that pushes at the red lines but subs for me have just shifted into accuracy tunning. I do enjoy pushing the high limits, maybe too much?. For subs, my accuracy starting line for 350 grain Maker uses H110 (seems to have a lower STD Dev as least so far) with 15.7 grain averaging 1030 fps from my 12" bolt. with about a 1.5 MOA. If the 'do not cross line' is 1050 fps for these then 16.00 grain seems to be too risky with a std dev that floats above that level. The sub 'go have fun' bullet now seems to be the Sierra SMK 300 grn for the cost. This one's starting accuracy line for me seems to be A1680, 17.30 grn with 2.700 COL (1077 fps - 6.7 std dev) and 1.0 MOA.

 

[SaltyDog89]

Not 225 but 210. Pressure signs high at 31.0 of A1680.

2/20/24
48F 42% 30.38in

Seekins and Mos-Tek 1:6.5
Garmin Xero

Barnes 210 GR TSX BT solid
A1680
Q brass x 2
FGMM 210M
BTO 2.6100
COAL 2.0670
COL 1.6775
29.5 1762, 1773, 1757
30.0 1837, 1799, 1794
30.5 1920, 1817, 1834 1” @ 100r COAL above is a typo..

 

[SaltyDog89]

Not 225 but 210. Pressure signs high at 31.0 of A1680.

2/20/24
48F 42% 30.38in

Seekins and Mos-Tek 1:6.5
Garmin Xero

Barnes 210 GR TSX BT solid
A1680
Q brass x 2
FGMM 210M
BTO 2.6100
COAL 2.0670
COL 1.6775
29.5 1762, 1773, 1757
30.0 1837, 1799, 1794
30.5 1920, 1817, 1834 1” @ 100

I'm guessing your COAL is 2.670 from above, not 2.0670.... Yea, I may be pushing it with 31.0 and clearly 32.0 grns is too hot. It is very strange to see how subs and barrel length work with the 8.6... My 12" bolt gives me 1824 fps (29.5 grn A1680); 1851 fps (30.0 grn A1680); 1893 fps (30.5 grn A1680). The threshold of longer barrel hurting vs helping seems to also dwell in this same powder area which is interesting.

 

[db2000]

I'm guessing your COAL is 2.670 from above, not 2.0670.... Yea, I may be pushing it with 31.0 and clearly 32.0 grns is too hot. It is very strange to see how subs and barrel length work with the 8.6... My 12" bolt gives me 1824 fps (29.5 grn A1680); 1851 fps (30.0 grn A1680); 1893 fps (30.5 grn A1680). The threshold of longer barrel hurting vs helping seems to also dwell in this same powder area which is interesting.

Yes thanks. Also, mine is 10.5” length. I added that and corrected the COAL.

 

[Stugots]

Consider IMR 4227 which is now my go-to powder for 8.6 BO. I'm getting sub MOA with my 1:3 Fix at 100 yards using 300 gr SMK.

What is your barrel length that you are using with this powder? Velocities?

 

[Stugots]

If anyone was interested, Precision Reloading has Starline 8.6 Blackout Brass on sale (ending today): https://www.precisionreloading.com/cart.php#!q=starline 8.6 blackout brass

 

[45-90]

What kind of accuracy were you getting with that load? Do you have a method for testing the subsonic expanding projectiles? Interested in how the slower twist is going to compare. I’m going to wait to order a Mos-Tek 8.6 barrel if it works out well with subsonic expanding projectiles.

My 6.5 twist 8.6 was much more accurate than then my torn rifled Faxon 3 twist.
I do not plan to hunt with any of the subsonic calibers...so it really doesn't matter to me...just wanted to check out manufacturers claims.
So I did a few expansion tests, just to see if they expand at all.
Just for personal information.
I had varying results.
Had many critics because it was water jugs and wet paper not ballistics gel, which only says they expand in ballistics gel...or not, or the petals break off...or not ..etc. Depending on velocity and twist rate.

Maker has 6.5 twist specific hunting subs in 338 300 gr, plus some supersonic expanding for 6.5 twist down to 165 gr.
They are twist specific, but the 350 Maker for 3 twist was accurate and did opened in the 6.5 twist.
But you'd have to test it yourself, and run the them on the high side 1050 to 1100 fps.
Too much velocity blows off the petals early or to little they open up much slower with respect to twist.
The medium makes a difference on expansion or bend.
Hornady just released their 338 ARC with an 8 twist, so their 307 gr sub should work in tbe 6.5 twist.
I just put together a 338 Spectre which is almost identical to the 338 ARC, but with a 6.5 twist.
But I ain't gonna hunt with any of them, unless it's a rabbit, might try to see if they expand on rabbit.

 

[st1650]

With the case capacity of the 8.6 BLK, how come no one has come out with a solid copper 400gr expanding sub ? Would be a perfect match for N105, N110, AA#9, IMR 4227. You'd get a good 75-80% case fill, lower SD/ES and you'd beat the 375 raptor without having to go with an oversized can.

 

[st1650]

My 6.5 twist 8.6 was much more accurate than then my torn rifled Faxon 3 twist.
I do not plan to hunt with any of the subsonic calibers...so it really doesn't matter to me...just wanted to check out manufacturers claims.
So I did a few expansion tests, just to see if they expand at all.
Just for personal information.
I had varying results.
Had many critics because it was water jugs and wet paper not ballistics gel, which only says they expand in ballistics gel...or not, or the petals break off...or not ..etc. Depending on velocity and twist rate.

Maker has 6.5 twist specific hunting subs in 338 300 gr, plus some supersonic expanding for 6.5 twist down to 165 gr.
They are twist specific, but the 350 Maker for 3 twist was accurate and did opened in the 6.5 twist.
But you'd have to test it yourself, and run the them on the high side 1050 to 1100 fps.
Too much velocity blows off the petals early or to little they open up much slower with respect to twist.
The medium makes a difference on expansion or bend.
Hornady just released their 338 ARC with an 8 twist, so their 307 gr sub should work in tbe 6.5 twist.
I just put together a 338 Spectre which is almost identical to the 338 ARC, but with a 6.5 twist.
But I ain't gonna hunt with any of them, unless it's a rabbit, might try to see if they expand on rabbit.

I plan to test both the MOS-TEK 1/6.5 and the Faxon remmage 1/3 with the 350REX with Tinstar ... Hopefully Faxon has improved their shit over the last year ... maybe.

I also got a few boxes of 280 LRX that were on sale that I will try as subsonic with tinstar. I don't expect any expansion but just want to play around with long range subsonic accuracy and see how they do

 

[DRWilson]

With the case capacity of the 8.6 BLK, how come no one has come out with a solid copper 400gr expanding sub ? Would be a perfect match for N105, N110, AA#9, IMR 4227. You'd get a good 75-80% case fill, lower SD/ES and you'd beat the 375 raptor without having to go with an oversized can.

It might be a stability thing. But I have not thought about this and will be call Paul and Maker to inquire about this.

 

[JR1200W3]

With the case capacity of the 8.6 BLK, how come no one has come out with a solid copper 400gr expanding sub ? Would be a perfect match for N105, N110, AA#9, IMR 4227. You'd get a good 75-80% case fill, lower SD/ES and you'd beat the 375 raptor without having to go with an oversized can.

I wonder how much does pushing a long(heavy) bullet down in a case(like the Creedmoor or 308 Win) reduces case capacity. What I mean by that is there is room along the side of the case wall in between the bullet shank. When you lay a gun down horizontal with a cartridge like that and a small subsonic powder charge, that powder has to sift down in between the bullet shank and case wall. How much of that becomes counterproductive for accuracy? And if you eliminated enough capacity by continuing to push that shank lower and lower in the case before the powder starts to fill side space?

 

[45-90]

The 350 gr Maker is heavy for calliber in 338.
What one gains by going to 400 grains would be mathematical enery at the muzzle, when limited to subsonic velocities.
But that may not necessarily equate to greater killing power, than say a 300 grain bullet...if both expand similar but both pass clear through the animal, dumping the excess energy into the ground.
I could actually machine a 400 gr copper bullet to see how long it is and how much case capacity, one has with respect to overall length.
One would have to make a .330" bore rider and. 338" driving bands to keep the start pressure low enough with fast powders not to have an over pressure event.

But in the end I doubt it would influence killing power much, unless you're subsonic hunting elephants, and really need a lot of penetration.
Busy now tumbling cases, annealing, for the AR 15 338 Spectre, have some 300 gr subs, and 165 expanding supers that would in theory give more range depending on if they actually expand at 900 fps and can work at 2100 fps as well...pretty big velocity spread, both bullets are designed for 6.5 twist, according to Maker, and could shoot them in the 8.6 Blackout with a 6.5 twist...still have to watch the speed and would recommend removing muzzle devices until ya know what the velocity limits actually are for your rifle, 2700 + fps in my 8.6 is a possibility, if they stay together.

 

[45-90]

Here is a .338 350 gr un modified Maker in a 6.5 twist AR 15.
It's a bit much. But it will fit 5 in a cut out mag and fit in the mag well.
I could lathe cut 20 grs off the front of the bullet or so to make an easier fit.
But its a light weight package mainly for subs with good powder fill.
I will explore its full potential, but expect supers to be kind of wimpy...we'll see.
Weather is horrible.

 

[45-90]

The 350 gr Maker weighed 346 gr out of the box others have been 347 gr.
So to easily fit the 346 gr maker to the AR 15 magazine I took of .055" off the point.
The results is 343 grs, only 3 grains of copper removed.
So if this works out in velocity...anyone who is interested in light AR 15 platform can actually have the same power as the 8.6 blackout in subs, with the 338 Spectre, with good case fill.

 

[Stugots]

city, brass or hybrid, bulle

Seems like there would be a bunch of subsonic data out there as that's what most are doing, it would appear...except me, I've been going full on supers from 160 gr 2800 fps to 350 maker at 1700 fps.
But I do shoot subs, the Maker recommended load for 3 twist was 1129 fps in my 6.5 twist, exceeding the 1050 max. But I haven't group shot it, but the supers in 350 Maker are very accurate.
I tend to shoot the 300 gr Berger 15.8 gr IMR4198 and the 300 SMK 15.8 gr of AA 1680 for subs. With accurate results.
They hit low on the target cause it was sighted for supers , but this is 300 SMK sub load with 1680 in the 6.5 twist.
And a Red Dot load, at close to max pressure, so 865 fps is about all there is, and it's so slow small velocity variatons, make a big difference vertically on the target. but it's quiet,

"I tend to shoot the 300 gr Berger 15.8 gr IMR4198 and the 300 SMK 15.8 gr of AA 1680 for subs. With accurate results."

Can you give me the case pressure for these loads? Curious to know your thoughts on the quality of Starline brass also.

 

[45-90]

The pressure of these loads is low, but depends on factors like case capacity, which differs from the type of case used, 45.1 to 47.2 grs of water capacity, and overall length the bullet is seated to.
But for example one of my reformed cases is 45.1 gr of water, with the 15.8 gr of AA 1680, and 300 gr SMK loaded to 2.785"
The chamber pressure is only 18,015 psi.
The 300 gr Berger with 15.8 gr imr 4198, loaded to 2.820" has a chamber oressure of 19,697 psi. Again low pressure loads.

Starline brass is fairly good in my book, I use it in a variety of calibers, rifle & pistol.

 

[Stugots]

The pressure of these loads is low, but depends on factors like case capacity, which differs from the type of case used, 45.1 to 47.2 grs of water capacity, and overall length the bullet is seated to.
But for example one of my reformed cases is 45.1 gr of water, with the 15.8 gr of AA 1680, and 300 gr SMK loaded to 2.785"
The chamber pressure is only 18,015 psi.
The 300 gr Berger with 15.8 gr imr 4198, loaded to 2.820" has a chamber oressure of 19,697 psi. Again low pressure loads.

Starline brass is fairly good in my book, I use it in a variety of calibers, rifle & pistol.

My plan is to use this brass, 300 SMK's and VV N32C. What weigh of powder do you suggest I start with? I'd like a subsonic load running around 1,050fps. TIA, Stu.

 

[st1650]

My plan is to use this brass, 300 SMK's and VV N32C. What weigh of powder do you suggest I start with? I'd like a subsonic load running around 1,050fps. TIA, Stu.

10.5-11.5gr for N32c depending on barrel length.

 

[Stugots]

10.5-11.5gr for N32c depending on barrel length.

Thanks, 16" barrel.

 

[45-90]

Thanks, 16" barrel.

I'm at 11.5 gr to 12.0 gr with N32C or Tin Star with the 300 SMK at 2.800" COAL for a 16" barrel. Start at top load and work down, if needed....depending on variables.
This should be an efficient load for the 8.6 Blk

 

[Dogtown]

I just got the latest data update for QL and it now has 8.6BLK, and my first barrel arrives today.

But I wonder if the case capacity listed is off, because a Case Fill of 39.1% sounds dangerous?

 

[st1650]

View attachment 8549567
I just got the latest data update for QL and it now has 8.6BLK, and my first barrel arrives today.

But I wonder if the case capacity listed is off, because a Case Fill of 39.1% sounds dangerous?

51gr case capacity seems waaaay to high.
Should be 43-45

 

[Dogtown]

Even then, case fill % seems really low. Of course I will defer to ground truth based on what people are actually shooting and it sounds like ~14gr of H110 with 300SMKs is good to go. It's just disconcerting that QL seemingly has it so wrong.

 

[st1650]

8.6 BLK has way too much case capacity for subsonics, that’s always been an issue. That’s why 338 ARC might be a better choice for the 300gr lead bullets.
One of my many reasons why I plan to use n32c for bolt gun loads, fill rate will be above 80%, it’s not temp sensitive and quite a bit faster burning than your N110/H110 loads.
Yet another reason why we need more 350gr+ long bullets to fill that big case.
Would also be nice to have a new bulkier powder in the burn speed of N105 but with N32c and trailboss gone, I wouldn’t hold my breath.

 

[Dogtown]

Oh yeah, I still have some Trailboss sitting on the shelf - will try that.

 

[45-90]

View attachment 8549654
Oh yeah, I still have some Trailboss sitting on the shelf - will try that.

Be sure your water case capacity is correct for "your" chamber...fired cases make the best vessel for that, whether your cases are made from 30-06, or 6.5 CM, or purchased Alpha factory brass.
Inaccurate data in, equals more inaccurate, and possibly dangerous load data out.

I still have a few pounds of TrailBoss, I don't usually recommend it for sub loads except bolt 308 W with 175 gr SMK 50BMG, and a few others.
TrailBoss doesn't operate bolt carrier in autos I've tried, that run great with other powders.
For bolt guns it's velocity is too low, quiet but leaves too much performance on the sub energy table.
Do not compress TrailBoss. It changes the burning characteristics 98 to 99 % fill is max no matter if pressure and velocity are still low.
For the 8.6 Blk with 300 gr bullets 15.8 gr 1680 was the most accurate with Auto and bolt 3 twist and 6.5 twist, with the 6.5 twist much more accurate.

For subs only the 338 ARC or very similar 338 Spectre are much better cases.
Plus a lighter AR 15.
I'm shooting the 338 Spectre with 6.5 twist. Case fill and pressures are higher resulting in better to complete powder burning.
First time out accuracy was very good with a variety of bullets 160 Barnes to 350 Maker.
The 350 Maker is a maximum effort bullet for this case.
The 160 gr to 315 gr will be better for the average reloader to persue, and easily fit the AR 15 mag without a cutout.

Also Your 47,862 MAP input pressure seems low, for supers and good brass I run 308 pressure since it's a 308 gun with shortened 308 brass...if you need more supersonic velocity, and the bullets can take the RPM of your twist rate.

 

[Mike6158]

What is the learning curve like for Quickload? Years ago I had software that was similar but a computer change and life contributed to me losing it. I have GRT but with the developer's passing I've hesitated to dive into it.

Also - By this weekend I should have my 8.6 bolt gun assembled. Solus short action. Preferred Barrel blanks barrel.

 

[DRWilson]

What is the learning curve like for Quickload? Years ago I had software that was similar but a computer change and life contributed to me losing it. I have GRT but with the developer's passing I've hesitated to dive into it.

Also - By this weekend I should have my 8.6 bolt gun assembled. Solus short action. Preferred Barrel blanks barrel.

It’s a little bit of a learning curve. The YouTube videos do help. And the efforts of @45-90 and others have really helped as well! I got it and glad I did. After about 30-60min, I was comfortable enough to use it.

 

[Mike6158]

Good deal. I don't think it would be a good idea for me to keep noodling around with wildcats without some way to confirm the load won't put a crack in the action, or my head.

 

[st1650]

Quickload is great and fairly easy to use but you really have to make sure your inputs are valid (garbage in, garbage out). A lot of the pressure calculation is based off the case capacity, the bullet (length, init pressure, etc) and the OAL vs the model so if those are wrong, for example if the case capacity is listed at 50 and your brass has 45gr of H20 and you have a load that's 59K Psi ... in real life you might be closer to 70K+. Same thing with temperature, powder compression, etc. Start low (or high in cases of subsonic) and do a sanity check with your chrono.
If quickload is showing you 1050 FPS and your first shot is 1400 FPS then stop immediately and look at your inputs. In my experience in a lot of subsonic load development, I usually aim for 1080-1100 FPS in Quickload and it gives me about 1020 FPS then I adjust charge or seating depth but I've never seen a > 125 FPS difference between the theory and the field - as long as your inputs are correct and barrel length as well.

 

[Mike6158]

I checked on Quickloads and apparently it comes on a CD. The laptop that I was going to use (runs my AMP press) doesn't have a CD player (yay modern "improvements"). I think I can buy one or I'll have to drag out an old laptop and install it on that.

 

[st1650]

I checked on Quickloads and apparently it comes on a CD. The laptop that I was going to use (runs my AMP press) doesn't have a CD player (yay modern "improvements"). I think I can buy one or I'll have to drag out an old laptop and install it on that.

You can get a cheap usb cd/dvd reader on amazon for really cheap.

 

[45-90]

The difference between the 8.6 Blk and 338 Spectre for the AR 15. Both have the 350 gr Maker. One has 6 grs. cut off and profiled for easy AR 15 mag fit.
The new 338 ARC will be very similar but with an 8 twist.
Next is a home built 178 gr deep HP from a 200 gr Speer, for sub or super....may have to slit it to open.