Which powder for supersonic 300 blackout in 1:7" twist barrel?

[darth_ritis]

I picked up a rifle in 300 Blackout and am setting up to reload for it. Powder is tough to find (read: impossible) but I'm curious which powder I should be hunting for? Supersonic loads with 125g slugs through a 7-inch twist barrel. I suspect H110 is the king but I'd bet some of you have some other ideas.

 

[FCS]

IMR-4227
AA-5744
Vit N-120
Lil' Gun - probably my top choice for 125s super sonic.

Is this for an AR or a bolt rifle? I'd assume AR (CMMG M300) based on your sig line but I don't like to assume.

If AR:
What is port size and location?
Trigger?
Buffer size (CAR or standard) and weight?

In fair bit of testing with different 300 BO ARs, all of the above had an impact on accuracy and how well rifle cycled.

 

[rjacobs]

For 125g then H110(or w296 same exact stuff) is best IMO. The mid weight stuff like 150g I prefer Lil-Gun as H110 didnt work quite as well for me.

 

[velillen]

I havent tried it with under 50gr stuff but i use AA5744 for my supersonics (150gr at 2k fps) and my subsonics (208's at 1050). Its very similar to AA1680 but the 5744 is a stick powder.

 

[darth_ritis]

Yes, AR, the CMMG. I bought it rather than built it, so these are mostly internal details I'm not aware of.

Port size - no idea. Location - about half way down the barrel. "Standard" trigger, whatever that means. Buffer size & weight - no idea.

 

[FCS]

Yes, AR, the CMMG. I bought it rather than built it, so these are mostly internal details I'm not aware of.

Port size - no idea. Location - about half way down the barrel. "Standard" trigger, whatever that means. Buffer size & weight - no idea.

Now that you've narrowed it down....I at least now know that the number of undefined variables exceeds the number of know variables by known amount. Lil' Gun is still going to be my recommendation. Worked well with 125s in 16" w/CAR gas system. Might not be ideal for pistol gas system but no worse then H110/W296 IMHO.

Good luck.

Make sure you have on eye and ear protection when testing.

 

[darth_ritis]

Thanks FCS!

Irony, luck, whatever - I was able to find some Viht N-110 and some Accurate 5744 this morning, so at least I have something to start with.

I'll keep looking for both Lil' Gun and H110. I shot my 7.62x25 Tokarev for the first time this morning and loved it, so I'll probably load H110/W296/N110 in it as well.

 

[BravoSector1]

I'm running a Remington 700 AAC-SD bolt action rifle in 300 Blackout using Hornady 150gn FJMBTs over 15gn of H110 with a velocity of 1,855. I shot a 2.2" group at 300 meters with those supers on Saturday. Very good load in this platform.

 

[Hoser]

Vhit N-110 and AA1680 have given me the best results. H-110 can be very temp sensitive and is really dirty. Even more so if you are running a can.