300BK subsonic

Daleo8803

Daleo8803

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Does anyone load for the 300BK in subsonic? I'm going to be building a pistol with the soul porpoise of shooting subsonic. Heavys like 200gr plus. Can u recommend a powder? Can I use coated bullets? Will they affect the gas system? Do I use a special buffer spring for the subs? Thanks
 
I like AA1680.
Pistol length gas is what you want.
Nothing wrong with coated or plated for subs.

Just be aware that 300 blk is a picky round to load for. Get a case guage.
You may need to open your gas port.
 
I built an 8.5" SBR. If I can ever get my flippin' stamp for my can I expect to shoot primarily sub's out of it. Mine will cycle sub's and supers with no changes to equipment. I'm running a JP captured buffer spring.

H110 (or W296 which is the same powder) is good; Lil Gun is suitable but I've only loaded a few test cartridges with it. Accurate 1680 was mentioned. Hodgdon has a new CFE Black powder that looks promising, too.

I started with the Palmetto Projectiles 208 grain coated bullets that have worked well for me. A friend has had good results with the Leatherhead coated bullets.
 
I have a 10.5" SBR that I load suppressed subs for:
Palmetto 203 gn coated over 8.6-8.8 gn H110/W296 with a SRP
gives me ~1050 FPS and it's actually overgassed with the can.

Coated have given me no problems with the gas system or with the suppressor.
 
I saw about 6 cans of 1680 on the shelf at Cabelas this evening...
 
I picked up a pound of Shooters World Blackout at a match a couple weeks ago. Loaded up 10.6gr under a 203gr coated pill from Palmetto Projectiles. They grouped very nicely, super quiet behind my can on a 10.5" SBR, felt softer but that may have just been coincidental. No change at all in POI from the 10.8gr A1680 load I had been using.
 
Be on the look out for Hodgdon's new powder CFE BLK, meant specifically for....you guessed it
 
Loaded some tonight, 174 gr Lehigh Subsonics over H110.
Tomorrow night I'm loading a batch with A1680.
Also use the H110 for Hornady 208 A-max's.
9" pistol length SBR with JP captured spring.
 
I've cooked up 150 gr subsonic loads out of ordinary FMJs. See here, but TL;DR: 9.8 gr of Accurate 1680.

I also load 230 gr bullets cast from a Lee mold and shake-n-bake powder coat them. They get 10.5 gr Accurate 1680.

I also have some 200 gr Eggleston Munitions coated projectiles, but so far I haven't had much luck with them. If I load them short enough that they chamber properly, then they nosedive on the feed ramps, but if I load them long enough to clear the feed ramps them the bullets jam up on the rifling in the leade. There may be a winning combination in there somewhere, but I haven't found it yet.
 
chiefjason said:
Groovy dolphins are my favorite fish!

I'm running a 22o gr round nose over H110 for subs. 9.6 gr IIRC. 16" barrel.
Click to expand...

dolphins are mammals, it wouldnt kill you to watch animal planet every once in awhile :p
 
jcalvinmarks said:
I've cooked up 150 gr subsonic loads out of ordinary FMJs. See here, but TL;DR: 9.8 gr of Accurate 1680.

I also load 230 gr bullets cast from a Lee mold and shake-n-bake powder coat them. They get 10.5 gr Accurate 1680.

I also have some 200 gr Eggleston Munitions coated projectiles, but so far I haven't had much luck with them. If I load them short enough that they chamber properly, then they nosedive on the feed ramps, but if I load them long enough to clear the feed ramps them the bullets jam up on the rifling in the leade. There may be a winning combination in there somewhere, but I haven't found it yet.
Click to expand...

how far do your 230s over 10.5gr go?
 
Daleo8803 said:
soul porpoise
Click to expand...

Great, now I'm picturing an aquatic version of Soul Man (Sam and Dave).

Just out of curiosity, is anyone building uppers in 300 BLK with anything other than a pistol-length gas tube? I'm not on the hunt for one, just haven't seen it and it's kind of strange to see a bunch of rifle-length barrels with pistol-length gas.
 
Zedhound said:
dolphins are mammals, it wouldnt kill you to watch animal planet every once in awhile :p
Click to expand...

Looks like a fish, wet like a fish, smells like a fish, swims like a fish, probably tastes like fish. It's a fish. lol
 
Lucky13bullets said:
Pistol length gas system gives you more options as far as powders that you can use to reload subs
Click to expand...

Yeah, I kinda understand the "why" (had it explained to me at a gun show - not sure I trust everything I hear at a gun show, but his explanation made sense). My question was less of an "advantages/disadvantages" and simply "has it been done" out of pure dumb curiosity.
 
Zedhound said:
how far do your 230s over 10.5gr go?
Click to expand...

I get about 1,000 fps out of a 16" barrel, and about 860 fps out of a 8.25" barrel. My range only goes out to 100m, but I can ring an IPSC steel silhouette all day long.

WeepingAngel said:
is anyone building uppers in 300 BLK with anything other than a pistol-length gas tube?
Click to expand...

My 16" upper has a carbine-length gas system. It's a cheapo Hardened Arms upper, but it works just fine. It struggles to cycle subsonics, even with a suppressor, though. If you were only going to feed it supersonic ammo, I'm sure carbine-length is fine. But as you've discovered, pistol-length is where it's at.
 
WeepingAngel said:
Just out of curiosity, is anyone building uppers in 300 BLK with anything other than a pistol-length gas tube? I'm not on the hunt for one, just haven't seen it and it's kind of strange to see a bunch of rifle-length barrels with pistol-length gas.
Click to expand...

I have Smith & Wesson M&P15, 300BLK, with a 16: barrel and a carbine length system. I'm using LilGun with heavy subs, gun cycles fine.
 
jcalvinmarks said:
I've cooked up 150 gr subsonic loads out of ordinary FMJs. See here, but TL;DR: 9.8 gr of Accurate 1680.

I also load 230 gr bullets cast from a Lee mold and shake-n-bake powder coat them. They get 10.5 gr Accurate 1680.

I also have some 200 gr Eggleston Munitions coated projectiles, but so far I haven't had much luck with them. If I load them short enough that they chamber properly, then they nosedive on the feed ramps, but if I load them long enough to clear the feed ramps them the bullets jam up on the rifling in the leade. There may be a winning combination in there somewhere, but I haven't found it yet.
Click to expand...
What Lee bullet mold did you use? I have been looking for the best one.
 
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