Powder question for reloading 300 Blackout Subsonic

[repiv]

I got a new AR Platform based rifle in 300 Blackout. I built it myself with Aero Precision and a Proof Research 16" Barrel with Superlative Arms Adjustable Gas Block.. I plan to shoot this suppressed and want to use heavier bullets and stay subsonic. I have Lapua brass because I use it for everything I reload in rifle. I use Redding Type-S dies for all other loads but they are not available for 300 Blackout without spending a ton of money and having the dies custom made for over $350 for the set. So I am using a LE Wilson full size bushing die for re-sizing and a Forster Ultra Micrometer Seater Die to complete the set. (This is the closest to a Redding Type-S set I could find) For Primers I am using CCI Benchrest Primers.
So now that I have the gun, the Lapua Brass, the CCI Primers and I know that I want probably a 208Gr, 210Gr, 212Gr, or 220Gr bullet to keep this Subsonic I need to choose a powder. So I am looking for input on choosing a Powder for keep a 208-220Gr bullet subsonic out of a Proof Research 16" Barrel with 1:8 Twist.

Thanks for the help.

 

[wvfarrier]

I use Lil Gun and H110 for both subs and supers. Havent had any problems. Hodgenreloading.com has a lot of load data

 

[newguy2k3v2]

4227 has been the quietest for me. I haven’t been able to get it to run reliably in a honey badger barrel but works fine in 8-10.5” so you probably wouldn’t have an issue.

Cfe blk was purpose built for this and runs every gun but it is louder to my ear

AA1680 cycles and is quieter than cfe to me but people say it’s dirty. Haven’t played with it enough to know for sure.

 

[padom]

I have an awesome CFE Black 220smk load...LC brass, 205, 205M and 450 all work great.. shooting it in a 10.5" Rainier Ultramatch...1055, crazy accurate and stupid quiet

 

[GrantB]

AA1680 cycles good and no adjustment needed for supers once you get it tuned up

 

[padom]

AA1680 cycles good and no adjustment needed for supers once you get it tuned up

Yep AA1680 is my favorite sub powder but I'm all out so.

 

[M4orturnate]

Keeping a semi auto quite and cycling is a balancing act. Lil gun is the best ive tried in both my blackouts(6"&16") for subs and supers but may not be for yours. Fortunately most powders suitable are still fairly cheap and obtainable. Pick up a few and try them

 

[mike278]

Shooter's World Blackout or CFE BLK both work great with 220 Nosler custom competition. The biggest issue I had was finding a magazine to keep the heavy bullets from nosing down and causing feeding problems. The Lancer L5AWM 300BLK magazines solved the problem and look pretty cool, too.

 

[Jonathan Swift]

Sw blackout left powder zombies all over everything for me lol, reloder-7 is an often overlooked sub powder

 

[redbullitt]

Cfeblk and 1680 are probably the easiest ive used to get it running with fixed gas, but as other said, they are noisy.

Lil gun does very well for a sorta quiet reliable load in a few ive messed with. Rl7 is indeed good too!

Ive had good luck with the cast and coated 250ish grain bullets too. May be worth a look.

Where it might get real interesting is with and oversized gas port, adjustable block and some fast powders, ie a sub specialty barrel.

 

[Old Man with Gun]

Big fan of Accurate 5744, quite and reliable.

My pet load is 10.5g with a 220g berry's spire point, 2.100 CCI 450.
I get 1050 from 10.3" barrels, 1030 from 8.3"

Barely flare neck and lee taper crimp, just enough to remove flare.

Cheap and 1 MOA accuracy with sorted brass if the rifle has the optics for it. I mostly shoot mixed brass and still get 1.5 MOA.

 

[bas402]

I have an awesome CFE Black 220smk load...LC brass, 205, 205M and 450 all work great.. shooting it in a 10.5" Rainier Ultramatch...1055, crazy accurate and stupid quiet

That doesn't look like a SMK?

 

[camotoe]

Looks like the old profile smk to me

 

[bas402]

Looks like the old profile smk to me

All I know is none of my 220 SMK’s have a cannelure.

 

[padom]

All I know is none of my 220 SMK’s have a cannelure.

Lol well they are 220smk.. says it right on the invoice.

Google is your friend....there are numerous articles, posts, info, pictures on these...they were produced specifically for 300blk subs if I recall for .gov. and had a bunch of overrun that were sold publicly. Dont quote me on that

 

[bas402]

Sorry, I don’t spend much time on searching things on google, so I presented the question that’s all. Since you brought it up though and indeed they were produced for the military in 300 blkout. Thank you

 

[Joeg26er]

Yep AA1680 is my favorite sub powder but I'm all out so.

hmm I have 8lb jug AA1680, also 8lb jug VVN110

 

[accurate obsession]

In a 9" barrel, AA #9 and 220gr projectiles, AA1680 is my backup. H110 and 125gr bullets for supers.

 

[wcoats]

I've tried several of the common powders (H110, A1680, IMR4227 and CFE BLK) and they worked ok and cycled my 10.5" AR with subs but most were really dirty when shooting subs. I switched to VihtaVuori N120 for subs and am very happy with it. It's a little more expensive but it is noticeably cleaner.

My current go to powders for 300 BLK are:
VV N120 for gas gun subs
H110 for 110-125gr supers
Trail Boss and Unique for stupid quite subs in my single shot Handi Rifle. But these will not cycle an AR

 

[wvfarrier]

CFE Blk was less Temp stable than Lil Gun or H110

 

[bigpeddler]

CFE Blk was less Temp stable than Lil Gun or H110

What kind of temp variation is this comment coming from? I have seen decent temp stability, but I'm 40F to 80F

 

[wvfarrier]

What kind of temp variation is this comment coming from? I have seen decent temp stability, but I'm 40F to 80F

Ive used it between +15 to +90 and have seen swings of over 100fps