300 blackout subsonic

[dellet]

I think if you start with similar load for 45acp then TiteGroup or Bullseye shouldn't be a problem. Work up from there is small conservative increases. I did a bunch of fire forming 223AI cases using the Cream of Wheat Method using 8.5gr-9.0gr Bullseye with remainder of case filled with cornmeal and a patch to plug the neck. Rifle chambers are stronger then a pistol chamber. Also, I'm not concerned about a pressure spike because of the significant jump that bullet must make to reach the lands when loaded to mag length in AR15.

There have been some discussions that in a super short barrel (shorter then 10") a true pistol powder may be the right answer for subsonics (fast, clean burn). Potential to edge out N110 and H110.

N105, #9 powders in that range will be about the fastest to reliably cycle without a lot of work to the buffer system.

Powders like tite group and Bullseye will go super or start popping primers before you get a standard weight bolt to budge.

Real quiet in your CZ tho.

 

[Oso]

N105, #9 powders in that range will be about the fastest to reliably cycle without a lot of work to the buffer system.

Powders like tite group and Bullseye will go super or start popping primers before you get a standard weight bolt to budge.

Real quiet in your CZ tho.

As always Thank You for insight. I know we spoke about this some time back. I will definitely make some for the CZ Bolt gun.

Do you see a noticeable difference between N110 and N105 for subsonics? I don't need to chase my tail on another powder if it isn't meaningful improvement for AR15.

 

[vegas]

This is IMPORTANT info here. I do all my subsonic load development without my suppressor on, target at about 25 yards so I can check for keyholing, and over a chrono. Darn suppressor cost waaaaay to much to be taking a chance.

Great advice. And how I do it. Work down with a chrono.

Oddly, I found a load elsewhere of 13.3gr of CFE BLK and 147gr milsurp bullets. Not a bullet weight I would associate with subsonic but works well. YMMV. Get's about 950 for me with a can, cycles well and is fairly quiet out of an 8.5" AR.

 

[Jody Simcox]

9.7 gr CFE BLK in an 8.5” suppressed, running 220’s...awfully quiet and cycles reliably