I have a partly built out AR lower. I've been adding pieces slowly and I've an end plate and castle nut on order. I have an unused carbine buffer tube, spring and buffer from an older gun that I put a VLTOR A5 stock kit on... Anyway, I've been wondering about the 6.8 as the caliber for my new build. Any 6.8 advice would be welcome on this thread. But my specific question is about buffers, weights and springs, and the like. Does the 6.8 do better with a heavy buffer? Should it have a particular set up for best performance? Thanks.