Let me suggest that you try some loads using 147 grain bullets. My son and I each have a 9mm 1911, and both guns hate both the 115 and 124 grain bullets, yet both shoot extremely well with 147grain bullets. I suspect that it might have something to do with the twist rate of the barrel. The next time you go to the range, take another gun since sometimes we just have bad days at the range. If your 1911 isn't shooting well try shooting another gun off that same rest. If the second gun shoots well, at least you can rule out a problem with the shooter. Still another option is taking a friend along. See if he or she gets the same 5 of 6" groups when shooting the 1911.