AR15 that cycles with subsonic .223

[mak91]

Yeah I know some will ask why While I like plinking with my 22lr conversion kits with subsonic ammo I hate how dirty it leaves the gun/suppressor and how much my eyes burn from the blow back of that sss 60grn stuff. So since I got my 7 inch 300 whisper to cycle with a short gas tube setup I figured a .223 should do the same. Its a 10 inch barrel with 1-7 twist and a gas port of .108 moved back 2 inches from a pistol position. It runs 55 - 80 grn bullets over 4.5 - 5.2 of trail boss. All subsonic and locks the bolt back on empty mag even without a suppressor. I had a gas block made up where the gas tube goes in on a angle, it makes it much easier to fit on the short setups, only needing slight bend to work.

[alorton]

Interesting. I didn't think that a subsonic .223 would have enough pressure to cycle the action. Did you have to use a low mass carrier or lighter than normal buffer?

While I don't imagine I'll build one, I am interested in the concept. Thanks for sharing. It always amazes me what people find out can be done despite the common belief that it won't work.

[mak91]

Nothing special about it except for the gas block and the port location, all standard mil spec 223 internals.

[thehouseproduct]

With a second gas block in the carbine position, it'd be a do it all gun.

[mak91]

Yup, I've already thought about that. I already have a 2 gas port 300 whisper ar15.