I shot some 255gr. WFNPB loads out of my 5" 1911 yesterday. I am using N340, N350, AA#9 and Enforcer. Velocities 850-1100fps. Leading was horrendous. When I use Cast Performance's 265gr. bullet at the same velocities I get no noticeable leading. Both are sized to .452. The only difference is the gas check. Am I most likely correct in believing a gas check will solve the problem? Any advice is very much appreciated.