Subsonic .223 loads

Buddy55

Novice
Minuteman
Jan 10, 2025
2
0
Austin, TX
I am interested in a subsonic load for home defense. I have researched the subject and there are a number of opinions. From what I understand, the lighter weight bullets will not cycle and they are single shot only, whereas the heavier bullets have a better chance at normal operation. I have some 77gr SMK and some 85gr Barn Burner bullets. I have a plan to work up, or work down, a load but I think it would involve too many rounds and a lot of time. So, without having to re-invent the wheel, does anyone have a load they have used that cycles the gun properly and remains subsonic? I have a .223 suppressor, and the gun is a 10.5 inch AR pistol. Before I get hate mail and too many other options for gun type and caliber, this is my plan and I would like to see it through. If my testing does not produce a viable round then I will look for alternatives. Thanks for you help.
 
Subsonic, the .223 would be worthless for energy. The optimum subsonic defense load with a 10.5" barrel is 300BO in my opinion. Subsonic .223 is essentially a .22 rimfire. If you don't want to reinvent the wheel and this is your goal get a .22RF upper in 10.5" and shoot 60gr bullets, lead. The bullets you list will perform horribly at subsonic velocites.
 
Well, I was hoping someone had a positive experience with subsonic 223. I was looking at 300BO but I don’t really want to add another caliber to my reloading bench, so I wanted to look at subsonic 223. Rats. I guess I found something the gun actually won’t do. Wow. My big concern was the flash, concussion, and bang if fired in the house for home defense. I have been to an indoor range and ,even suppressed, the 223 seemed to have a pretty noticeable bang, whereas I e seen 300BO suppressed at the indoor range and they were awesome. Well at least I can use the existing lower if I switch to 300 BO. Thanks for y’all’s input.
 
IF you ever get 223 subs to cycle an AR, it would have to be a special built gun dedicated to those rounds only. Not sure that's even possible. But sub 223 is pretty worthless in anything other than a bolt action. 22LR subs for the win.
 
.224 sub pull action repeater wouldn't be my first pick for fighting lol.

It will be a waste of time effort and powder if goal is a serious rifle.

and at least 22lr bullets can expand lol.

Sounds like you need a 300 blk or 9mm to be honest.