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.