I was looking at a Mega Arms 223 upper kit that had their 10.5" barrel but it had a 1:8 twist. The quality looks great and I already have the lower but I wasn't sure if I should stick with a 1:7 twist. I will be mostly shooting 55 gr Federal. Any thoughts if I will be lacking with the 1:8?
I think the 1/8 will be fine and give a little more flexibility if you decide to shoot anything heavier.
Faster twist for heavier bullets. Slower for lighter. Either one would be indistinguishable in a pistol application neither will keyhole.
The 12in I did I shot with no problems. I did drill the gas hole out on the barrel a little,per watching some vids from ar15.com My 10in build I never shot,but the guys who bought it made a couple adjustments and it did fine. I can not say what the accuracy was on the 10in gun as I sold it before "I" shot it
