I'm looking for load data for sub loads and 223 . 10-1/2 " pistol AR if that matters . It works great in my blackout , can't find any data for 223 ? HELP !

What weight bullet? What twist rate? Sierra has “normal” data with Reloder 7 but not subsonic. It seems a bit slow for sub use, are you expecting the gas system to function?




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My 300bo does cycle with 11 grains and a can , but not without . Was hoping to get my 556 to do the same . 1-7 twist . 55- 77 great bullets.

Grain

It's gonna be tough to get the 223 to subsonic while still having enough port pressure to run the action.

Another option is a CMMG 22 Rimfire adaptor. My 1/7 10.5" did reasonably well with 40gr Federal Target, and Aguila 60gr subsonic. Didn't like CCI Velocitors.

can't speak for an AR, as I am a bolt guy....

but around 10 grains in a bolt gun will work with RL 7

seems like a 221 Fireball would be a better choice if ya were doing a new barrel