Back To Top
Join Date: Oct 1999
Location: 3D, Luzerne County
Just about every AR now is chambered in 5.56mm which you can also shoot .223 ammo. There is no need to look for a special chambering.
It's not the pressure of the 5.56 round that it an issue, but rather the OAL of the round. While the 5.56 may have greater pressure when fired in a true .223 chamber, the 5.56 may often have a longer bullet when compared to the .223 round.
The longer round in a true .223 chamber could greatly increase the pressure, possibly damaging the rifle.
I have two AR's; a Bushmaster and a S&W MP Sport, both with 5.56mm chambers. Both can shoot .223 and true 5.56mm ammo.