handloading for the 300 AAC Blackout

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dfirstcolonync

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I added the 300 Blackout to my 30 caliber stable. In searching the caliber for bullets at Midway, the selections are very limited but all are listed as .308 caliber. Looking for advice from real world loaders on this. Can any ..308 bullet be used? There are a myriad of bullets and weights for the other 30 caliber rifles. Why not the Blackout? Specifically asking about powder and charges you are using as well as bullets for high velocity as well as sub-sonic loads. I considered using my Hornady SST's in 150 and 165gr for high velocity and moving up to the Speer 200 and 220 grain Grand Slam for subsonic. I'll be punching these out of my 10" SBR AR platform. BTW, Seller&Belot factory loads run about 60 cents per round. It might be hard to beat that economically after buying brass, bullets, powder and primers on top of a die set. What you say?
 
If you want velocity, drop down to 110-125 gr bullets.
For subs, most cup-and-core bullets running 190-230 gr work just fine. (~170-220 gr for solid copper or brass.)

If you want to hunt with something that will reliably expand, the options get extremely limited. The best options, right now, are the 110 gr Barnes TAC-X (supersonic) and LeHigh Defense 194 gr Maximum Expansion (subsonic).
Hornady is supposed to also have a heavy bullet intended for subsonic hunting, and does list loaded ammunition on their website. But the bullet is not yet available as a component. ...And I haven't even seen the loaded ammunition 'in the wild'.

Most bullets originally designed for other purposes aren't going to expand as intended at .300 Blk velocities - especially if run subsonic.


My personal loads that I have decided to keep in circulation use:
H110 (I run subs almost exclusively.)

Hornady 208 gr ELD-M (targets, small game)
9.3 gr at 2.250" COAL w/ CCI #41 primer, Win brass

Hornady 220 gr RN (Plinking / small game. Burning up leftovers from my .30-40 Krag - but they work very well and are cheap(ish) to buy more.)
9.4 gr at 2.100" COAL w/ CCI #41 primer, R-P and Win brass

Lehigh 194 gr Maximum Expansion (larger game)
9.X gr at 2.210" COAL w/ CCI #41 primer, S&B brass
--I used LeHigh's recommended charge of 9.7 gr here, but found it to be supersonic with about 60% of the shots fired. I need to back off a couple tenths and retest.

None of the above have been across a chronograph, that I can remember. For subs, I test for function, accuracy, and supersonic cracks. If it meets the first two requirements and isn't giving sonic cracks, it's good.

Applicable rifle details, if desired:
Standard Franken-AR SBR lower, based on an Aero Precision receiver.
AR Stoner 10.5" barrel. (Unknown port size. It works, so I don't care.)
Pistol gas.
Standard gas block. (Non-adjustable.)
SilencerCo Harvester .300. (A Chimera may take its place.)
 
Yup, pretty mich any 308/309 bullet will shoot. Will it run the gun? Thats another question all together. I run as low as 110 grainers up to 230 grain cast. Still working on getting my 230s running reliably. H110 and 4227 are the powders I use.
 
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Be careful, if using the Hodgdon's annual, of the OAL's and loads for CFEBLK; some of the OALs recommended for the 208 grain bullets lead to compressed loads at even the minimum load of powder. I've contacted Hodgdon about the issue.

I use Hornady XTP 150's loaded ahead of 17.0 grains of CFEBLK, OAL 2.070, as a standard round; That's actually below Hodgdon's recommended minimum of 18.8 grains of CFEBLK but it a shorter OAL than recommended. The 17.0 grains chronos at 1731 fps with an 11.8 SD.

I load two different subsonics; 11.6 grains of CFEBLK behind a Hornady 208BT, OAL 2.250, runs 1099fps from an 18" barrel and cycles every time. With the same bullet and OAL, 10.0 grains IMR4227 runs even slower at 1.016 fps and occasionally doesn't cycle my pistol AR. The IMR4227 load has an SD of 16.9, the CFEBLK is more than twice that at 39.5.

And yes, any 308 bullet.
 
I use the 125gr Speer TNT for targets, The 120gr Barnes TACTX and 125 Nosler ballistic tip for hunting. I’ve heard good things regarding the Hornady SST. Check out 300blk.com for more info.
 
Check out 300blk.com for more info
Click to expand...

The forum is “300blktalk.com”. Im there under the same user name. There are a few stickies of pet loads. Lots of GREAT info on that forum.

Here are my suggestions.

Super sonic loads. H110 is prob your best bet at getting top velocities
110gn tactx (blacktip)
125gn SST
120gn tactx
I run 125gn SMK (blems) as practice ammo.

The new 150gn Speer golddot is showing A LOT of promise. Good expansion at Blackout speeds. Holds that velocity better then the lighter offering. There is a thread about that bullet going on right now.

For subs, i load 208gn Amax with 1680. Its not the quietest powder, but it runs an AR easily. You will NOT get that bullet to expand at all. Just not in the cards in that caliber. But, it shoots good and can be had fairly cheaply.

Im running an AAC 9” SBR with a Gemtech can, and it functions in all 4 modes with the above ammo.
 
OP mentions cost of brass. I make my own out of 5.56 brass. I have buckets of range pick up 5.56 brass. 30 dollar harbor freight chop saw and a 40 dollar jig and you are in buisness. Chop it resize it and run it through the Giraud power trimmer. You can make a bunch of it pretty quickly. My son and I made a 5 gallon bucketful in a day.

Reloading options are practically endless. I usually use pulled 148 FMJ that can be found very reasonably on line. I can get 5 holes touching at 50 yards with the 148's and H110.

I recently started working up loads for 220 grain coated lead bullets I get from steel valley casting. (local guy). I have no plans to hunt with it so I am not concerned about expansion.

Just about any 308 bullet works.
 
My go-to 300BLK suppressed subs load is the 220 Leatherhead coated bullet with 9.8 gr of Accurate 1680 and i'm at about 1010 fps from my 16" carbine. The 220 SMK's needs a slightly increased charge of 10.7 gr and im at about 1030 fps. I actually get slightly better accuracy from the 220 LH's. Which is FINE by me as shooting those 220 SMK's gets mighty expensive real quick !
 
I was told NOT to use .311-.312 sized bullets, maybe it does not have enough safe pressure to clear the barrel.
 
I concur, 300blktalk.com is well worth looking up. I too am there under the same user name as here but I haven't posted there in a while. I have a H&R single shot in this caliber and I load it like a modern .32-20 and my loads wouldn't cycle an AR15...

Tony
 
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