Although it's not an AR 15, I think there is enough knowledge here to answer this one. Have a Tikka T3 in .223 and I mistakenly bought Hornady Match in 75grain weight sent via UPS, no return policy. The barrel twist is 1 in 9 and it had stuck in my head that you need at least a one in seven twist to shoot the heavy bullets. What performance can I expect from using the Hornady 75 grain match in this twist. Remember it is a bolt action rifle if that makes a difference.