8.6 Blk reloading info

[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.

 

[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.

 

[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.

 

[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.

 

[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.

 

[DRWilson]

I finally have my 8.6BLK assembled and ready to go. I'm short on lighter bullets. I have some Barnes 225gr TSX BT to start with. Of course Barnes doesn't have load data for the 8.6 but they do have load data for a short action .338 210gr bullet. The cartridge is a .338 Federal. The case is 0.4-ish longer. I may have some IMR 4198 but I don't think I have anything else they list. The starting load is 10 gr-ish over case capacity so all in all... not a good fit for estimating an initial load. Not having Quickloads is starting to be a pita.

The short version of the paragraph above - I guess I'll try AA1680 and the 225gr TSX. It's not my favorite powder of the powders I have. Neither is CFEBLK but I'll probably try that too.

FOR 5-6.5 TWIST ONLY:
There is data in this thread for 1680. I would strongly suggest skimming this thread and starting a gr to .5 gr below those loads. For H335 (supers only, i'd start at 35gr). My load in a 16" barrel is 37gr, I could easily get away with 36.5-36.8gr.

for subs, I use H110 at 16gr. in my 350 bullet loads. For subs, the data for 3 twist is a good starting point but DO NOT use any of the 6.5 twist super data for 3 twist.

your 10gr suggestions seems to low.

 

[DRWilson]

That wasn't a suggestion what I was getting at is the starting load for a .338 Federal (bigger case but still short action) was roughly 10gr over the case capacity of the 8.6BLK.

For the record - I wouldn't attempt to use any .338 Federal load.

I've got posts all in this series. I stepped away because the two 3 twist AR's that I had were overwhelmingly disappointing and I wanted to wait for my Proof Research barrel (24") and Solus action to arrive before I posted anymore.

I'm not a fan of 1680. I didn't have great results with the 3 twist barrels in an AR. I've got powders that fall all around 1680 on the burn rate chart but no load data. That's up to me to come up with. I have the benefit of being able to step out my back door, set up a bag, a Garmin Xero, and collect my own data. That said, I'll probably try 1680 at some point. I have "enough" that's for sure.

H110. I need to check to see how much of that I have.

I need to get Quickloads coming...

Perfect!! the rifle looks sweet.

 

[45-90]

Here's the rifle, all 16 pounds of it. It balances good on the tripod. Especially with the Wimberley head. I can set the mount height so that the barrel is centered on the pivot point. It tracks smooth that way.

The scope won't stay on this rifle. It's a bit much for the service.

View attachment 8553947

I like the rifle but 16 lbs is a bit heavy for me to pack around...but it's your gun, so build it to your preferences.
When going to the 6.5 twist I shoot cheap lead Speer bullets, for few reasons besides the price and cheap practice, especially supers.
For instance lead is shorter than copper for the same weight, plus less start pressure to engrave rifling.

So you get higher velocities, and more energy on target. So I run the 225 gr Speer at 2407 fps ave in the 8.6. Which would be close to 338 Federal velocities, and most likely kill a truck load of hogs, without the expense of copper...but thats up to you.
Just got some Maker bullets in today, to shoot for fun...I'm not hunting.
Pictured is the 350 gr for 3 twist, the 300 gr sub and 165 gr are for 6.5 twists.
The 165 gr is called an expanding super, notice the saw slits down the bullet, and built for 338 Spectre.
It could be of interest to 6.5 twist 8.6 shooters. I've hit 2800 fps with the Barnes 160 gr but this is made for lower velocity and could fit some short barreled super applications. Might get 26 to 2700 fps if it would stay together at higher speeds.
It seems to have a fairly large expansion velocity range (Not for 3 twist.) with 6.5 twist 2100 to 900 fps but that would definitely have to be confirmed before hunting with it.

 

[45-90]

Went shooting the 338 Spectre today.
I'm getting to like this little cartridge.

All loads were dropped from a powder measure and loaded on a Dillon progressive, ...none were individual weighed out, except the first one to get the correct charge for each bullet.
Results every load is single diget S/D regardless of powder used.....except one load was 12 with home made bullets.

Accuracy was very good, as I am trying to shoot left handed, because the right eye has eyesight that went south...and it feels awkward
The 300 SMK load will go through one hole as 5 out of 7 did, but getting lefthand shooting down with an AR seems odd.
The 160 gr Barnes was a bit more accurate than the 165 Maker.
The 178 hp hit 2100 fps, so this and the 338 ARC are pretty much identical, but this has a 6.5 twist rather than an 8 twist.
Maker already has bullets made for 6.5 twist.
The smaller case capacity takes almost no effort to get single digit S/Ds, and very accurate loads. Every bullet exhibits accuracy, no bad groups all day. Three different powders.
Copper bullets, cheap Speer lead bullets, or Sierra match bullets, were all getting good groups.
It's a very efficient cartridge, better for subs than the 8.6 but lacking the supersonic power of the 8.6.
So each is a bit of compromise, IMO.

But for subs only and an AR 15 this little cartridge was way better than my early AR 10 in 3 twist, which wasn't accurate, with huge S/Ds , even supers were disappointing in the rough 3 twist barrel, with only copper.
The cheap lead 200 gr Speer can be run at 1960 fps in the Spectre but 1400 fps in the AR 10 3 twist these lead bullets tend to blow up, plus no accuracy.
Just my experience and why I like the 6.5 twist for both of these calibers.

 

[db2000]

Seekins SP10 Mos-Tek 1:6.5 10.5”
Garmin Xero

11/24/24

300 gr SMK HPBT (factory seconds)
A1680
Q brass x 2
BTO 2.0130
COL 1.6805
COAL 2.759
17.0 959, 1021, 1014, 989, 1009, 1011, 1004, 1021, 1010, 1003 stable
17.5 1063, 1040, 1051, 1059, 1029, 1035, 1029, 1050, 1032, 1063 stable

Maker 350
A1680
Alpha brass new
FGMM 210M
BTO 2.4000
COAL 2.7910
COL 1.6775
16.0 910, 869 not stable @ 50
16.5 917, 918, 927 not stable @ 50
17.0 942, 959 stable @ 100
17.5 1025, 1000, 1003, 1008 not stable @ 50
18.0 1043, 1030, 1022, 1028, 1024 decently stable 50/100y

Barnes 210 GR TSX BT solid
A1680
Alpha LRP new
FGMM 210M
BTO 2.0615
COAL 2.6625
COL 1.6775
30.5 1801, 1848, 1827, 1825, 1832 SD 15.4 ES 48 MLP
31.0 1851, 1874, 1858, 1867, 1863 SD 8, ES 24 1.25” MLP

Hornady 230 ELD-X
A1680
Alpha LRP new
FGMM 210M
BTO 2.0170
COAL 2.7575
COL 1.6775
26.0 1574, 1528, 1516, 1528 NP
27.0 1581, 1591, 1596, 1582, 1591 SD 6 ES 16 1” NP

 

[st1650]

Seekins SP10 Mos-Tek 1:6.5 10.5”
Garmin Xero

11/24/24

300 gr SMK HPBT (factory seconds)
A1680
Q brass x 2
BTO 2.0130
COL 1.6805
COAL 2.759
17.0 959, 1021, 1014, 989, 1009, 1011, 1004, 1021, 1010, 1003 stable
17.5 1063, 1040, 1051, 1059, 1029, 1035, 1029, 1050, 1032, 1063 stable

Maker 350
A1680
Alpha brass new
FGMM 210M
BTO 2.4000
COAL 2.7910
COL 1.6775
16.0 910, 869 not stable @ 50
16.5 917, 918, 927 not stable @ 50
17.0 942, 959 stable @ 100
17.5 1025, 1000, 1003, 1008 not stable @ 50
18.0 1043, 1030, 1022, 1028, 1024 decently stable 50/100y

Barnes 210 GR TSX BT solid
A1680
Alpha LRP new
FGMM 210M
BTO 2.0615
COAL 2.6625
COL 1.6775
30.5 1801, 1848, 1827, 1825, 1832 SD 15.4 ES 48 MLP
31.0 1851, 1874, 1858, 1867, 1863 SD 8, ES 24 1.25” MLP

Hornady 230 ELD-X
A1680
Alpha LRP new
FGMM 210M
BTO 2.0170
COAL 2.7575
COL 1.6775
26.0 1574, 1528, 1516, 1528 NP
27.0 1581, 1591, 1596, 1582, 1591 SD 6 ES 16 1” NP




View attachment 8555243View attachment 8555244

What accuracy were you getting with aa1680 at 18gr ?

 

[45-90]

I found the 350 Maker stable at 880 fps, shot at 64 yds on the test day with a 6.5 Twist with 5.2 SD in the 338 Spectre with W 296 into 1/2".
They were good in the 8.6 Blk too at the 52 yd test distance, bullets were touching in the same hole, with the same speed when testing 8 or 9 different powders.
According to Berger twist rate calculator, your 6.5 twist should be stable at -20°, 0 altitude, and 750 fps, with the 350 gr Maker.
Maker produces a 300 gr 6.5 twist specific, along with several others, like the 165 gr supersonic expanding available...I was shooting today.

 

[db2000]

What accuracy were you getting with aa1680 at 18gr ?

I only loaded 5 of each for velocity and shot 3 at 50 and 2 at 100, so hard to say. They weren’t perfect holes but not keyholes either, hence “decently stable”. That’ just a note I make for myself. I’ll load more now and start further investigating.
I like the 338 Spectre round. Looks promising!!

 

[st1650]

Unsurprisingly, the published loads for tinstar were way off
12in Faxon 1/3tw remmage barrel, brand new alpha brass
11gr N32c tinstar Barnes LRX 280 @ 2.66in light crimp with Lee die gave me 830 FPS

I'll go straight to 12.5gr but I'm worried I might run out of capacity for the Rex 350 as they are about .2in longer and heavier. Maybe I'll try loading them at 2.85in and adding a bit more headspace via the barrel nut.

At 14gr I might start running into pressure

 

[st1650]

12.7gr N32c 285 LRX @ 2.82in - 930FPS
14.0gr N32c 285 LRX @ 2.82in - 1010 FPS
No pressure signs at 14.0 yet.
This barrel is crazy slow. I don't see N32C working with the 350 REX once I get them. Probably have to go with Alliant Green Dot or Blue Dot. What a shame, the SD/ES are really tight with N32c.

 

[45-90]

All one has to do is change the profile of the 350 gr Maker to reduce case capacity from 27.2 to 17.5 gr of H2O capacity.
Gets pressure up, fill ratio up, and most of the powder burned.
I made a 338 bullet from a 750 gr lathe turned 50BMG bullet.
Picture one the lathe turned bullet is longer than the Maker but seats a full neck length of the case deeper...where the .338" diameter begins, the forward is bore rider.
While the Maker is already in the smaller diameter where the saw cuts are...so it has to be seated out farther, to get to 338" bullet diameter, leaving too much powder space.
One can see the difference the backs off the bullets is where case capacity can be visualized....the 350 Maker is way down there.
Change the bullet design add a little weight and a few more relief cuts, and it would improve the performance of the 8.6 Blkout subs, and have plenty of room for supers.

 

[45-90]

I wasted some good 50BMG bullets to mess with bullet ideas for these .338 sub cartridges. Even a long skinny bore rider so one could shoot it at higher velocity, single load down the barrel.
It gave me something to do...

 

[Dogtown]

It’s a mixed bag. Some it’s spot-on from the start, others take some massaging of values. What I tend to do with a new cartridge I haven’t shot yet is compare QL values vs a series of published data. Understanding that the published data can be pretty conservative, you can usually tweak the case capacity and powder Burn Rate / Heat to make it match the book or get it at least closer.

But just remember that QL isn’t ground truth - it’s just a simulator designed to give you roughly ballpark results. Don’t count on it to be very accurate until you tune it with your own data.

 

[45-90]

Yes QL is only a ball part guess.
Always use published data.
First use published data to compare, you need their exact data they used.
Many reloading manuals do not give you enough data. Like case volume, of brand used.
Then use their data on one specific powder, their case capacity, bullet lenth, bullet construction input, barrel length.
Put in the max powder charge listed say 30 gr produces 52,000 psi their manual max like from Hodgdon data.
Add their data to QL adjust the powder "burn rate factor" just a little at a time to match the 52,000 psi...
Powders are blended and do not burn exactly the same from lot to lot, plus they do not burn the same from cartridge to cartridge...but the case volume, bullet length for a specific bullet and case capacity are relatively close to the same as is your barrel length.
Do not change factors that are known to be true.
Check QL velocity with manual velocity.
It should be pretty close.
Using the same data and burn rate factor change bullets in the same case, and change bullet weight and lenght if actual bullet used.
Type in manual max charge with manual stated bullet ....QL and manual will be close.
Repeat this several times, and get close comparison with the manual and this powder.
Then when a heavier bullet not listed is used and all the correct physical data input for that cartridge and case, Only.
You might, just might, have a starting point for your new heavy bullet, if you reduce the powder charge and actually shoot it ...and check actual velocity against predicted velocity....look for pressure signs.
I like QL and use it where nothing is printed on wildcats.
It can be a useful tool or garbage...the more you use it and understand its purpose as just a guide to help you from blowing your face off. Common sense still prevails, if you don't think the recommended powder charge is correct, or especially dangerous do not use it.
I try to put out only data I've actually fired in a rifle... but sometimes people just want data, and don't understand the principle of QL, it's many times along way from exacting, and it's not for everyone.

 

[Dogtown]

Do not change factors that are known to be true.

Rule number one.

 

[DRWilson]

Is there any data on barrel life yet? What should I expect from the slower twist barrels running supers?

 

[45-90]

Is there any data on barrel life yet? What should I expect from the slower twist barrels running supers?

The 8.6 Blackout is a small capacity case, with a big bore. And many loads will be low velocity subs and intermediate loads, probably 10,000 rds per barrel...maybe more.
I use to shoot 308 Win LR to 1400yds back in the day 17,000 rds of the same exact match load, before changing components.
Each 308 Win barrel was taken off after 8000rds and I chambered a new barrel to go the next 8000rds.
The 308 is a smaller bore with more powder, and all 8000 rds were high pressure loads.
It's been years since I've worried about barrel life because I'm in a good position, I have the chamber reamers and lathes to chamber a new barrel so it only cost the price of a new barrel blank, which only takes about 7 days from order to deliver, and chamber and thread the next day and done.
So I don't do round count these days, no more competition shooting to worry about whether it's me or the barrel rd count .

 

[DRWilson]

How about a barrel with supers only? Still the same thought on a long life barrel?

 

[45-90]

How about a barrel with supers only? Still the same thought on a long life barrel?

Yep, don't worry about it, the accuracy should be good for 8000 rds minimum.

 

[45-90]

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.