Figuring out a powder

[Cluck Norris]

I have almost all of the parts the throw together a upper for a 300black out, bcg from a spare upper, slicksided upper floating around from lord knows what, a barrel that was in the spare parts box that I got from a guy when I worked at a gun store, and a cheap rail from that same box, all I am missing a gas tube and think I can get one from a Guy at work for a box of 00 buck.
So all in all I would be in the upper for next to noting.
In today’s market I think I am going to have to reload ammo to be able to shoot it at all, and I will not be shooting it ton but would like to verify that it is operational, plink with it some, and use it as a hinting load.
So here’s my list of questions ...
Is there a powder that will work well for both 556(55gr and 62 gr) that will work well in a 300black out set up?
If so what have you had the best success with?
Is there a powder that will do the above and be able to go between subsonic and supersonic 300 blackout loads?

 

[Toprudder]

I don't load 300 BO, but a quick look through some load data, I don't see any powders that cross over. Most of the 300 BO loads use magnum pistol powders. The fastest burning 556 appropriate powders are still way slower burning that anything I see listed for 300 BO. That makes sense, in 300 BO the bullets are heavier, and the case volume is less, compared to 556.

 

[Michael458]

I don't load 300 BO, but a quick look through some load data, I don't see any powders that cross over. Most of the 300 BO loads use magnum pistol powders. The fastest burning 556 appropriate powders are still way slower burning that anything I see listed for 300 BO. That makes sense, in 300 BO the bullets are heavier, and the case volume is less, compared to 556.

100% spot on.

To answer your question, one powder for all..... NO.............223 is a completely different animal than 300 BLK.

To further answer your question, for 300 BLK I have found nothing better than WW 296 overall. WITH higher velocity loads and 100-110 gr bullets, which is most of what I do with 300 BLK.

SubSonic and SuperSonic 300 BLK....... NO, I think you will want two different powders here as well........

Life is a bitch, and there is alway a cost! Unfortunately.

 

[Bluejay75]

Unless you’re shooting cast. 2400, AA9, 5744 and 3031 will work in both. With gas enough to cycle reliably.

Run subsonic jacketed with any of the 4 listed above in 300 BO. And supersonic 300 BO with 2400 or Accurate 9.

But you’re then shooting reduced loads in 223. 2400 was developed for the 22 hornet to give “2400” FPS. I think you can get to 25-2600 in 223 with the right bullet.

You can make it work if you play with the application of the cartridges. But there’s quite a few combinations that can be had with the powder selection above.