8.6 Blk reloading info

Reloaded some 8.6 for the first time and tested them out yesterday. Just cooked up 4 rounds of each and they were shot using my 8.6 BLK gas gun, with 8" barrel through my Dead Air Primal can. Velocities captured with Magneto Speed v3.

Reloading Setup:
Q/Gorilla once fired brass, Hornady Custom Grade dies, sized to specs using Sheridan gauge, brass was right around 1.790" after sizing.

First load:
Barnes 210 gr TSX
2.650" COAL
29.5 grains, Accurate 1680
Unknown large rifle primer
1694 fps average MV
I was not out shooting for accuracy as I was mostly just seeing if this was going to blow up my gun or not, so no comments there. I believe this round was way over pressure even though Faxon/Q chart said the MV on this should be more like 1750 fps, believe I saw some unburnt powder as well sitting on the bench after shooting. Attached a picture of the brass after shooting, which was already pretty beat up from the original firing, but more for showing the primer came back and flattened fairly significantly.
super.jpg


Second load:
Gorilla 285gr Subsonic Fracturing Projectile
2.750" COAL(had nothing to base on, so went with this)
14.5 grains, Accurate 1680
Random large rifle primer
980 fps average MV
Again, I was not out testing for accuracy, but was much more pleased with this round than the other one as far as performance goes. Faxon/Q chart for a 300 gr Sierra SMK was at 860 fps with 14.7 gr of powder with an 8 " barrel, so clearly there's some disconnect here as well. I was well above the final circumferential cut on the bullet, so maybe I was a bit too deep which drove up the pressure and velocity? Gun functioned well and locked back after each shot, ejection wasn't much to speak of as far as distance goes, but was at least coming out around 3-4 o'clock.
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I would not take the Hornady customer service comments as gospel, wait for SHOT, although Hornady seems to have done all their new products announcements when they announced 7PRC. I'm still on the sidelines waiting for factory brass, I just don't have the time, money, space to convert brass. I can only hope a few things:
a) some blanks that are little slower, but not 1:10 slow (threaded 3/4x24 would be ideal for me) - anyone seen anything?
b) factory brass or a bigger "factory" ammo support

I have a CGS Hekate waiting for this cartridge to move just a little further, hopefully shot show we see a few more companies jump in. Faxon really is the only big company to step up, Q still doesn't even have a can for it. I also think we forget how long 300 whisper took to perfect and become the 300 blackout of today.
 
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Brass is prepped and primed to do some load development tomorrow.

The Sheridan case gauge is an awesome tool when getting set up to make brass for the first time.

Mocked up a round with the COAL at 2.600 using the 185 CX

View attachment 8028864
Where are you getting the Sheridan case gauge? Search for Sheridan case gauge gives me a Sheridan engineering and coming up with a dead page. Also is anyone making modified cases for OAL gauges? Any help would be appreciated. Thanks
 
Where are you getting the Sheridan case gauge? Search for Sheridan case gauge gives me a Sheridan engineering and coming up with a dead page. Also is anyone making modified cases for OAL gauges? Any help would be appreciated. Thanks

If you're on a VPN you may be having issues, but the page just loaded for me.
 
I would not take the Hornady customer service comments as gospel, wait for SHOT, although Hornady seems to have done all their new products announcements when they announced 7PRC. I'm still on the sidelines waiting for factory brass, I just don't have the time, money, space to convert brass. I can only hope a few things:
a) some blanks that are little slower, but not 1:10 slow (threaded 3/4x24 would be ideal for me) - anyone seen anything?
b) factory brass or a bigger "factory" ammo support

I have a CGS Hekate waiting for this cartridge to move just a little further, hopefully shot show we see a few more companies jump in. Faxon really is the only big company to step up, Q still doesn't even have a can for it. I also think we forget how long 300 whisper took to perfect and become the 300 blackout of today.

Diligent defense has an 8.6 can. Looks very nice in person.
 
Looks like they're selling pretty well! I'm not sure what the original production numbers were...

I made the initial request 9/1/2022. I said I needed one, and I felt there was a potential market. On 9/5/2022 I got an email from Laura Sheridan that it was not on any production list yet. On 9/6 she emailed me again saying it was now on the list, so they might be available by the end of 2022. By the end of November she notified me they were available, so I ordered one the same day. That was pretty darn good service!
I got one too.
 

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I finally got some range today today to test my subsonic loads. 16 inch AR build, CCI Small Rifle Bench rest primers, cases made from Federal 6.5 Creedmoor, projectiles Sierra Match King 9300T.

I used 4 powders, in 5 steps each, 3 rounds per step.

These are strictly my findings and can be used as information, NOT RELOADING GOSPEL! With the lack of support from all the manufacturers, I hope this will help someone trying to build subsonic rounds. These were NOT tested with a can installed. I used a MagnetoSpeed V3 chrono.

View attachment 8031953

IMR 4227 was a disappointment. Groups were poor until the loads reached supersonic speeds. Last Round Hold Open did not work until I was well into supersonic speeds.

Best groups were obtained from Accurate 1680, with TAC close behind. I plan to go back with some additional loads for TAC - as it looks like it can go above 17gr.

With so little powder used, it will probably require slapping the mag before inserting to get all the powder in the rounds in the same place for consistent groups.

Info from others working up subs would be appreciated.
8.6 Blk. Subsonic Work Up UPDATE:

25 yard indoor range, linear compensator from Tromix.
Measurements taken with a MagnetoSpeed V3 chronograph

FPS = 5 shots averaged

Sierra SMK 300 gr.

Powder:
Accurate 1680 16.5 gr 1088 FPS

Powder:
TAC 18.0 gr 1084 FPS

Powder:
CFE BLK 17.0 gr 1088 FPS

OAL:
2.670”

I have decided to go with TAC. The groups were better and more consistant. Accurate 1680 didn't always lock the bolt back at this powder level. This is a 16" barrel with carbine length full gas. Groups printed about 1/2" lower than supersonic at 25 yards.

I used nickel plated cases that I formed from Federal 6.5 Creedmoor SRP. I annealed them before cutting and sizing, then turned the case neck to fit the 8.6 Sheridan gauge. There was no damage to the fired cases.

USE THIS INFORMATION ONLY AS A GUIDE! Your results may vary.
 
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8.6 Blk. Subsonic Work Up UPDATE:

25 yard indoor range, linear compensator from Tromix.
Measurements taken with a MagnetoSpeed V3 chronograph

FPS = 5 shots averaged

Sierra SMK 300 gr.

Powder:
Accurate 1680 16.5 gr 1088 FPS

Powder:
TAC 18.0 gr 1084 FPS

Powder:
CFE BLK 17.0 gr 1088 FPS

OAL:
2.670”

I have decided to go with TAC. The groups were better and more consistant. Accurate 1680 didn't always lock the bolt back at this powder level. This is a 16" barrel with carbine length full gas. Groups printed about 1/2" lower than supersonic at 25 yards.

I used nickel plated cases that I formed from Federal 6.5 Creedmoor SRP. I annealed them before cutting and sizing, then turned the case neck to fit the 8.6 Sheridan gauge. There was no damage to the fired cases.

USE THIS INFORMATION ONLY AS A GUIDE! Your results may vary.
25y was your max testing range? Are you sure it’s a carbine length gas? If it is then that explains the 1680 not locking back.
 
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Just joined the forum. Been working my stuff up getting ready for Nyala and Giraffe in June.
Faxon 12” on a Remington 700

Sub = 285 Eld-M w/ 15g of A1680 out of new Hornady 6.5 brass
I’m getting 975-1000fps (4000 ft elevation)

Needing a supersonic non-expander for Giraffe so I ordered some Hornady 250g RN Interlock.
I might be regretting it if they separate. Glad to hear the warning about shooting naked first! Might’ve saved me a Can.

What do you think a safe “starting “ charge with 1680 would be? 20g?
 
Hiya folks, there are other case options for 8.6 brass if you don't want to trim and neck turn. In looking for brass, I came across this (https://dallasreloads.com/product/8-6-blackout-brass-only/) about resizing 6mm GT brass to 8.6 BLK. Did some math, and then bought 100 cases from Mid South Shooters. Lubed up the cases and set up my HDY AP press with 6.5CM -> .308 -> 8.6 dies (with expanding balls dropped as low as possible and "half pulled" the cases to expand out the neck. Then did "full pull" resizing with the 8.6 die to bump the shoulder back and viola! 100 rounds of perfect length brass. No pooching/folding/bubbling where the neck meets the shoulder, no collapsed shoulders, they fit a Sherridan gauge perfectly and the finished cases come out to 1.683", with a bit of room to grow. Yeah, it's $0.75/case and some folks have a ton of 6.5CM Hornady brass just lying around. However, I'm a fan of small rifle primers for 6.5CM cases and all of my brass is either Starline or Lapua, so neck turning would have been in my future. This gets me 8.6 brass *and* a SRP, so I don't have to try to find LRP in the current environment.
 
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Hiya folks, there are other case options for 8.6 brass if you don't want to trim and neck turn. In looking for brass, I came across this (https://dallasreloads.com/product/8-6-blackout-brass-only/) about resizing 6mm GT brass to 8.6 BLK. Did some math, and then bought 100 cases from Mid South Shooters. Lubed up the cases and set up my HDY AP press with 6.5CM -> .308 -> 8.6 dies (with expanding balls dropped as low as possible and "half pulled" the cases to expand out the neck. Then did "full pull" resizing with the 8.6 die to bump the shoulder back and viola! 100 rounds of perfect length brass. No pooching/folding/bubbling where the neck meets the shoulder, no collapsed shoulders, they fit a Sherridan gauge perfectly and the finished cases come out to 1.683", with a bit of room to grow. Yeah, it's $0.75/case and some folks have a ton of 6.5CM Hornady brass just lying around. However, I'm a fan of small rifle primers for 6.5CM cases and all of my brass is either Starline or Lapua, so neck turning would have been in my future. This gets me 8.6 brass *and* a SRP, so I don't have to try to find LRP in the current environment.
Yup this works I can confirm that…but have you loaded solid copper projectiles in it yet? Without a chamfer in the case mouth you’ll get a copper ring forming in your chamber over a period of time from bullet scoring when seating the bullet.
 

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Tried some penetration Supers today. Hornady 250g Interlok RN. Yeah… bonded.
25gr of A1608 and I had flat primers, stuck bolt and a punched primer at 1500fps.
The good news was that the bullets stayed together and grouped

Gotta get a slower powder. Waiting for some 250g monoliths later this week… 🤞🏻
 
Glad to see this thread is still active. I was away due to internet provider "issues" and I am old and weird so I don't do certain things on my phone. But I got stuff up and running again and if I can find another chronograph (smoked my old chronograph trying out some Nosler partition bullets) I am going to work on some more CFE BLK load work ups. I noticed a couple of other people had some good results with it. I put up my data with my YouTube video. It's very basic. I have a local shop working on resizing some brass for me and might have some data on that as well. We'll see.

 
Just started loading this morning. Cutting Edge Raptor ESP 225 (with insert, so 230g)… CFE BLK. with 27.3g I’m getting 1650 and 1 - 1.25 moa at 100y.
Problems with crimping though. The CE’s are only riding with 2 ridges inside. My crimp keeps them in but you can bump them in further if you handle them roughly.
Any idea?
 
Just started loading this morning. Cutting Edge Raptor ESP 225 (with insert, so 230g)… CFE BLK. with 27.3g I’m getting 1650 and 1 - 1.25 moa at 100y.
Problems with crimping though. The CE’s are only riding with 2 ridges inside. My crimp keeps them in but you can bump them in further if you handle them roughly.
Any idea?
On further reflection, fl sizing die was too deep. I think that’s fixed now🤞🏻
 
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Tighter seating now. Dropped OAL to mitigate pressure spikes… My groups opened up to about 2 - 2.25 moa. Should’ve done one thing at a time.
OAL back up now. Groups tightened a smidge. Somewhere around 1.5 - 1.75”. I’m good with that.
I have 4 loads now, practice, medium game & 2 extreme large game penetration loads. Think it’s time to stop knit-picking and enjoy it.
 
Etsy sells a jig for the Harbor Freight miniature chop saw. Works great! I anneal and then chop, then bevel.
I have the harbor freight chop saw. I got a trimmed case and put it in the saw vise. Pushed the case against the blade and marked the vise with a marker where the case/shoulder meet. I can get the cases cut spot on. Then I trim them to length before sizing them. Makes life so much easier.
 
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I added a 3D printed 8.6 guide from Etsy. It uses a ball bearing to lock the case in proper setting. I've done over 300 rounds on it. I also had a problem with my Harbor Freight chop saw. The blade mount acted like a clutch, causing the blade to fit somewhat loose. I modified a bit so the blade would fit much tighter. Much easier and quicker cut now.
I don't have much faith in harbor freight tools, you get what you pay for. When I start to cut a shell and the blade penetrates the wall for some mysterious reason the vice loosens up a little. It didn't have that problem the first 200 rounds I cut. What I do now is after turning it on, I have 1 hand lowering the blade and 1 hand turning the adjustment knob. Soon as the blade penetrates the wall the adjuster will tighten up 1/8 of a turn and you can finish the cut otherwise it will bind the blade. I've done another 200 this way. I imagine with a fixed jig you don't have this problem.
 
I took the base off for the jig install. You are correct about the cheeeeep vice. Once I got the jig tweaked and the loose blade fixed, I've cut several hundred rounds with no problem. It just chops really quickly throught them and I'm still on the original blade.

I leave a little of the shoulder, which seems to make sizing easier, and then I clean up the length with the RCBS trimmer with bevels.


View attachment 8066264
That's similar to the way I work things. I start by trimming my brass with the chop saw to 1.687. Then I get my 6.5 RCBS 3-way trimmer and trim it to 1.685. This way I am running the expander ball through the least amount of neck. I have a turret press and put a 308 neck sizing die on 1 station and the 8.6 nextdoor. I open the small amount of neck open with the 308 and then size it down with the 8.6. It seems to grow about 1.5 which is fine with me, even though I have a 338 3-way cutter. It's done, trimmed, chamfered, and deburred. Easy-peasy.
 
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That's similar to the way I work things. I start by trimming my brass with the chop saw to 1.687. Then I get my 6.5 RCBS 3-way trimmer and trim it to 1.685. This way I am running the expander ball through the least amount of neck. I have a turret press and put a 308 neck sizing die on 1 station and the 8.6 nextdoor. I open the small amount of neck open with the 308 and then size it down with the 8.6. It seems to grow about 1.5 which is fine with me, even though I have a 338 3-way cutter. It's done, trimmed, chamfered, and deburred. Easy-peasy.
Work smarter not harder
 
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I use the universal deprimer as my first step, then I anneal before cutting on the chop saw to 1.73" (I like to save a little neck lip) because they fit my annealer better full size, and it cuts easier annealed. I chamfer the edges of the rough cut and then clean the cases because I don't want any foreign junk in my die, which can leave imprints on the brass. I size the pre-cut brass because is is much easier on the die. I use a large amout of RCBS #2 (baby snot) on the case. Too much on the outside of the kneck/shoulder area can cause shoulder wrinkles. I just roll the lube on from a pad, and occasionally lube the inside to make it easier to pull. I then run them throught the RCBS Trim Pro2 case trimmer which trims to final size and chamfers inside and out using an attched power drill. I then clean again to remove the case lube, add primers and powder. I've done several hundred and fired them, and this seems to be working OK.
What type of annealer do you have? I need to get one but I'm not to crazy about dropping 2K for one?
 
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Alright. I learned a hard lesson today. When Q says "only bonded and solid copper projectiles" they mean only solid copper.

I had some 185gr .338 federal fusion (bonded) loaded to very mild pressures, that came apart from the ultra fast twist and took out every single baffle, and the end cap, in my supressor.

Word of warning...test fire projectiles without supressors to verify they are staying together.
Been there, did that 2 weeks ago, although I lost a chrono as well. Steep learning curve and gave me excuse to get a MagnetoSpeed from a Caldwell.
 
Anyone do any further testing on 308 conversion vs 6.5? I have a TON of 308 and not a whole lot of 6.5 laying around at this point. I ordered some 8.6 dies and have an on press trimmer. Would be only loading 8.6 for subs anyways so the % load to case volume shouldnt be an issue talked about on page one but just wondering if anyone has ironed out more of the forming differences from those two parents?
I load almost exclusively off of 308 range pickup. I anneal, full length resize to .338 (WO mandrel), OAL trim, Neck trim, Resize with mandrel, then case check Sheridan cut out gauge. The only issue I run into is some LC and odd named brass, the case lip diameter is a few thousands to large for the Sheridan gauge and those I chuck up in a drill and file down slightly till they fit. Although they still fit my Aero 308 BCG fine. I do it to make sure it fits full length.
 

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Well, a 1:3 twist rate at 1,000 fps has the bullet doing the same RPM as a 1:9 twist at 3,000 fps. I don't believe I've ever heard of complaints of that 300gr bullet not holding up to a 1:9 @ 3,000.

Or, just load some up without the suppressor and shoot them to find out. You should be doing that anyway for any suppressed loading.
Subsonic is fine it more when you push it out around 1500 fps on these you get into the grey area...
 
Today I had a double-tap (Actually, the range officer I Iet shoot it had the loose grip) I have fired several hundred rounds through it with no problems. When I cleaned the gun today, a piece of mangled copper fell out of the linear compensator.... had a few mangled threads on the inside of the compensator. Does anyone think this happened during the double-tap because of the fast twist? This was a 185 gr. Hornady CX.
I don't load the 185 CX over 31.6gr of 1680 you can go more but you risk it coming apart. 31.2 is where it shoots good for me 16" AR Faxon. Also lost a linear comp and a chrono found out the hard way.
 
Been there, did that 2 weeks ago, although I lost a chrono as well. Steep learning curve and gave me excuse to get a MagnetoSpeed from a Caldwell.
I joined your club today, always wondered what the inside of a suppressor looked like. Liberty suppressor is going to love the 8.6 guys.
IMG_20230206_094710596_HDR.jpg
I can’t say too much but I’ll be testing a 1:6 barrel as soon as I get the barrel manufacturer to spin it up. The 1:3 was overly hyped and isn’t necessary. I spoke to several reputable barrel and bullet manufacturers who all agree the 1:3 isn’t ideal and they’ve confirmed even a 1:7 will stabilize the majority of heavy projectiles.
 
I can’t say too much but I’ll be testing a 1:6 barrel as soon as I get the barrel manufacturer to spin it up. The 1:3 was overly hyped and isn’t necessary. I spoke to several reputable barrel and bullet manufacturers who all agree the 1:3 isn’t ideal and they’ve confirmed even a 1:7 will stabilize the majority of heavy projectiles.

I'm interested in how your slower twist barrel does with regards to solids and cup and core bullets. The 1:3 seems to be way more of a pain than a benefit.
 
185 CX at 2100. Shot the first pig in the head at 70 yards, dropped it and it got up and went 10ft before dying. Second one was at 160 walking away. Had to lead it a foot and held 9” high, rolled it on thee first shot, but had to put 4 more into it.
Pigs are tough… but still.
Thank you. I’m trying some heavys. 285 subs and 230 CE copper Raptors (1600fps). But I’ll be taking larger game. Fingers crossed.
 
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185 CX at 2100. Shot the first pig in the head at 70 yards, dropped it and it got up and went 10ft before dying. Second one was at 160 walking away. Had to lead it a foot and held 9” high, rolled it on thee first shot, but had to put 4 more into it.

What's the velocity envelope for good expansion supposed to be with that bullet? I'm not familiar with that one, but wondering if your impact velocity was at or below the lower threshold.
 
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https://www.americanrifleman.org/content/throwing-copper-hornady-s-cx/
Per this article: "Hornady suggests a striking velocity of at least 2,000 f.p.s. as the minimum for CX bullets to expand to 1.5 times its bullet diameter. To test this, I handloaded 165-grain CX bullets fired from the .30-’06 to hit the papers at a velocity of 1,800 f.p.s. The bullet penciled a hole through the paper 11" deep and came to rest with only the loss of its Heat Shield tip. The bullet nose had only opened to 0.375", not much more than the bullet diameter."
 
Appreciate the info in here. It was the guide for my first brass conversion and loads. I have never converted brass, short of necking up/ down available brass. It took a bit, but thank to this thread it wasn't too difficult.

285 ELDMs, over 16.8gr of CFE black. Converted Hornady 6.5 brass. Right at 1k. Had test loads up to 17.5gr. At 17.2 the primer just began to flow and I'd shoot it no prob. At 17.5 the primer flowed, but was not flattened, extraction was normal. I'd call it the edge of what I'd shoot if was a super accurate node and I wanted the speed, but I'd expect shorter primer pocket life. I didn't chrono, but jacket held up fine. About 2k altitude and 40*.

I have some 350gr Maker Rex's, on the way I have CFE Black and Lil gun available. Anyone have a starting point for either of those?

Thank you!

We've been unusually cautious thanks to you pioneers. No can or muzzle device, and target at 5yds to check for jacket frag before risked the can and magneto speed.

Rifle is 12.5" Henry Long Ranger. (1:3) It's wearing a Delta optics 1-6x now. Gonna do a quick chrono with some custom ammo we received, and then it's getting cerakoted back to a factory look.

It is both, fun and quiet. Looking forward to doing more testing.

86blackout2.jpg
 
Appreciate the info in here. It was the guide for my first brass conversion and loads. I have never converted brass, short of necking up/ down available brass. It took a bit, but thank to this thread it wasn't too difficult.

285 ELDMs, over 16.8gr of CFE black. Converted Hornady 6.5 brass. Right at 1k. Had test loads up to 17.5gr. At 17.2 the primer just began to flow and I'd shoot it no prob. At 17.5 the primer flowed, but was not flattened, extraction was normal. I'd call it the edge of what I'd shoot if was a super accurate node and I wanted the speed, but I'd expect shorter primer pocket life. I didn't chrono, but jacket held up fine. About 2k altitude and 40*.

I have some 350gr Maker Rex's, on the way I have CFE Black and Lil gun available. Anyone have a starting point for either of those?

Thank you!

We've been unusually cautious thanks to you pioneers. No can or muzzle device, and target at 5yds to check for jacket frag before risked the can and magneto speed.

Rifle is 12.5" Henry Long Ranger. (1:3) It's wearing a Delta optics 1-6x now. Gonna do a quick chrono with some custom ammo we received, and then it's getting cerakoted back to a factory look.

It is both, fun and quiet. Looking forward to doing more testing.

View attachment 8071457
This is amazing. I need one of these in my life.
 
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https://www.americanrifleman.org/content/throwing-copper-hornady-s-cx/
Per this article: "Hornady suggests a striking velocity of at least 2,000 f.p.s. as the minimum for CX bullets to expand to 1.5 times its bullet diameter. To test this, I handloaded 165-grain CX bullets fired from the .30-’06 to hit the papers at a velocity of 1,800 f.p.s. The bullet penciled a hole through the paper 11" deep and came to rest with only the loss of its Heat Shield tip. The bullet nose had only opened to 0.375", not much more than the bullet diameter."

I guess that explains the results @evilsvt saw. With a muzzle velocity of only 2,100 fps, it's pretty likely that impact velocity was somewhere below 2,000 fps.

The little 300 Blk gets away with similar velocities for supers because of the large selection of varmint bullets that still expand at those low speeds. But it seems like almost all .338 caliber bullets are designed for higher velocities of larger cartridges, so the 8.6 Blk doesn't enjoy that same benefit. I wonder if the creator genuinely thought this 1:3 twist would make up for it, or if it really was just hype all along?
 
Would people here be so kind as to share their Maker 350gr REX load data? I found that with my 8" barrel, the following works from a muzzle velocity perspective:

15.5gr of Hodgdon Lil Gun + CCI 200 LRP + 2.810 COAL = 1057 fps
17.3gr of Hodgdon H110 + CCI 200 LRP + 2.810 COAL = 1042 fps

I have not grouped these rounds yet, so I do not know how accurate these loads are. The problem I have run into, though, is that they are having trouble chambering rounds from Magpul PMAGs in my Aero M5 upper/lower. It happens when I release the bolt to chamber the first round in the magazine and the bolt will ride over the top of the brass and cause a jam (picture below). I spoke to my gunsmith about the issue and he advised that the rounds are riding the shoulder guides. He said I could file down the shoulder guides in the magazines to prevent this, but I was curious first if anybody else has run into this issue and had any luck getting around this with a different COAL or perhaps a different magazine.

1676310418424.png
 
Hit by the splody bullet on Saturday. Berger 300gr OTM Hybrid Tactical (thicker "skin" than the hunting versions) in a ladder test of A1680 from 15.8-16.8 in .2gr increments across a Magnetospeed v3 for subsonic testing (2400' elevation). First 15.8gr round was 1022fps while second didn't register. Weird... Shell ejected, but no hole in target. Uh-oh... It appears the bullet exploded when it hit the brake. Cracked the brake and the pieces gouged and shorted out the Magnetospeed sensor. I cautiously continued. Shot 20 total, 19 were good with MOA or better accuracy and one exploded. FSCK. Will continue with brake (it just adds character) but had to order a new sensor. Tried this bullet as a current boutique ammo manufacturer is offing the same bullet in a subsonic cartridge for sale. Hmmm....
 

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Hit by the splody bullet on Saturday. Berger 300gr OTM Hybrid Tactical (thicker "skin" than the hunting versions) in a ladder test of A1680 from 15.8-16.8 in .2gr increments across a Magnetospeed v3 for subsonic testing (2400' elevation). First 15.8gr round was 1022fps while second didn't register. Weird... Shell ejected, but no hole in target. Uh-oh... It appears the bullet exploded when it hit the brake. Cracked the brake and the pieces gouged and shorted out the Magnetospeed sensor. I cautiously continued. Shot 20 total, 19 were good with MOA or better accuracy and one exploded. FSCK. Will continue with brake (it just adds character) but had to order a new sensor. Tried this bullet as a current boutique ammo manufacturer is offing the same bullet in a subsonic cartridge for sale. Hmmm....
So did the bullet explode because it hit the brake or did it explode from the rotational force? Or is it unknown?