10-31-2011, 02:34 PM
I would take as many buffers as you have to the range with you. If you want a common buffer between both calibers, it will depend on your 5.56 gas system and dwell-time set-up as well. A 16" barrel with a carbine-length gas system is probably one of the hardest on the action, and will run better with an M16 carrier first, then whatever buffer weight balances out the system with the ammo you use, and the gas port diameter that it has. A smaller gas port will provide a milder impulse, while a larger will be more voluminous per time, and usually sharper in the same set-up. A 16" mid-length or even rifle-length gas system is easier on the system, since the gas port pressure is lower. What type of 5.56 upper do you have?