3000 is not realistic out of 16 inch barrel. I have lots of chrono time with AR's. You have 3 things working against you. The carbine length gas tube bleed off pressure very early in the pills travel and the 7 twist slows down the bullets travel. Then length of the barrel.i wanna get a load put together using 223 in a 16 inch AR barrel with 1-7 twist using 55 grain nosler ballistic tips at over 3000 fps is this possible ??