From a standard 223 you will be hard pressed to do this SAFELY. With H335 and a 40gr bt with a 26" tube I did get 4040 fps from my 223 Ackley.
I can believe that a I run 40's at 3900+ out of a 22" 223AI.
Having run the 223AI to both primer piercing and once case separating pressures I have no illusions that my pressures are not close to the edge nor the velocities many other post.
