IMO Carbine length gas system is ideal for 10.5 - 14.5" barrels. A 16" with carbine length gas system, no matter how small the gas port is drilled, can still be very over gassed. They will function fine and maybe put a little more wear on your BCG, but a properly gassed 16" mid length will have a smoother and lower recoil, and run a little cleaner.
I go with these for 5.56, all assuming properly sized gas port or adjustable gas block. Other lower pressure calibers like 300 BO or 7.62x39 have different optimal gas lengths.
<10.5" pistol length gas
10.5-14.5 carbine length
14.5-16 mid length
18+ rifle length
I go with these for 5.56, all assuming properly sized gas port or adjustable gas block. Other lower pressure calibers like 300 BO or 7.62x39 have different optimal gas lengths.
<10.5" pistol length gas
10.5-14.5 carbine length
14.5-16 mid length
18+ rifle length