300 Blackout Subsonic Powders

[My Toy]

I purchased a suppressor for my Remington 700 /w 16" treaded barrel in 300 blackout. Still probably 5 -6 months away from actually being able to take possession of it. Anyway loaded up my first try at subsonic and chronographed them yesterday. The two loads were: 1. 194 gr Lehigh Max X, CCI-450, Starline unfired brass and 9.6 grs W296. 2. 190 gr. Hornady Sub-X, CCI450, Starline unfired brass and 9.6 grs W296. The powder charges were the loads listed on the Hodgdon Website. The 9.6 gr. charge weight of W296 was the only charge weight listed ( ie. no starting charge weight). Both loads produced in the neighborhood of 1190 FPS. It is my understanding you've got to get below 1100 fps to really be subsonic. I've read in multiple places the admonition about reducing W296 below recommendations. The only way to get these loads below 1100 fps that I see is to reduce the powder charge. Doesn't seem like a prudent idea. So I'm asking advice from experienced subsonic reloaders? I also have some Lil'Gun if anyone has ever used that. What are other powder recommendations?

 

[4g64loser]

Aa1680.
2400
Imr4227

If you are bot seeing coking down the shoulder/case body, you can reduce a bit of charge weight.

 

[atblis]

N120 is arguably the best.

 

[Squaregrouper]

I have always used H110 with 220gr pills. Load around 10gr and use a chrono to tune from there. In my 8.5" SBR 10.0gr gives me around 1050fps.

 

[erwos]

I've read in multiple places the admonition about reducing W296 below recommendations. The only way to get these loads below 1100 fps that I see is to reduce the powder charge. Doesn't seem like a prudent idea. So I'm asking advice from experienced subsonic reloaders? I also have some Lil'Gun if anyone has ever used that. What are other powder recommendations?

CFE BLK, Accurate 1680, and SW Blackout are fantastic powders for subs, and can also do a pretty credible job with supers at higher charge weights. Also have a lot of use in 7.62x39 reloads if you're into that.

 

[outrider58]

A 1680. I've tried many recommended powders and always came back to Accurate.

 

[ohen cepel]

IMR 4198, Lil Gun, and H110 is what I tried with 220 Pro Hunters. Lil Gun had an edge on accuracy as I recall, but I found all good for me from a bolt gun.

 

[teratos]

A 1680. I've tried many recommended powders and always came back to Accurate.

I first met you when we went in on some 1680. lol.

 

[outrider58]

I first met you when we went in on some 1680. lol.

Still works and we're still friends.

 

[mtlcafan79]

You don't need any of these gas gun powers. I use 6.4gr of N320 behind 220gr Sierra RN pills in a single shot 300blk setup. Keep the velocity below 1000 fps, preferably closer to 900 fps to keep it out of transonic region and it will be a lot quieter.

 

[outrider58]

You don't need any of these gas gun powers. I use 6.4gr of N320 behind 220gr Sierra RN pills in a single shot 300blk setup. Keep the velocity below 1000 fps, preferably closer to 900 fps to keep it out of transonic region and it will be a lot quieter.

Yeah, I'm not doing dynamic entries with a single shot. Lol

 

[Park ranger]

My 194 Lehigh load is 8.1 of lilgun. 975 fps

 

[4g64loser]

Yeah, I'm not doing dynamic entries with a single shot. Lol

Never seen you so dynamic entry in a stack but I've seen you try to do a surprise disengagement.

 

[mtlcafan79]

Yeah, I'm not doing dynamic entries with a single shot. Lol

I wouldn't dynamic entry with a bolt gun either, but that's what OP has. He doesn't need the extra gas that 1680, Lil gun, H110, etc. generate. In my experience loads that are borderline subsonic in a gas gun will go super in a manual action.

 

[Melnic]

9gr of H110 under a Lee mold once powder coated is about 230gr
Subsonic at about 1050fps

I recall someone mentioning H110 was very close to lil gun for load data.

quiet once suppressed.

 

[outrider58]

Never seen you so dynamic entry in a stack but I've seen you try to do a surprise disengagement.

Lol

 

[4g64loser]

Lol

Dynamic entry next year.

 

[lazarus]

Yeah, I'm not doing dynamic entries with a single shot. Lol

I really feel like there is a "that's what he said" joke in there.

 

[erwos]

I wouldn't dynamic entry with a bolt gun either, but that's what OP has. He doesn't need the extra gas that 1680, Lil gun, H110, etc. generate. In my experience loads that are borderline subsonic in a gas gun will go super in a manual action.

Barrel length is probably a much bigger factor than action. That said, at least for me, if I'm gonna go to the time and expense of loading a bunch of subs, why not use a powder that will make them work a semi-auto in a pinch, too? PSA and BCA both sell cheapo uppers for lolzing purposes, it's not a big investment.

 

[outrider58]

Dynamic entry next year.

White light too?