RE: GM .54 Bore Size....................
Just so you know, I have a .535 LEE mold that I casted two hundred roundball out of. They were so hard to load, I never made another batch. They did make dandy ammo for my wrist rocket sling shot thought. I use a .530 becauseI am not driving nothing down the barrel with a mallet. You should of seen my friend and I that day trying to load them .535 ball. We had to ram atree with the ramrod in order to seat the first one. The second one, I used a ball puller and removed. I bought the mold because some "expert" told me that was the size ball they shot. Try the ones you got. Loading these rifles should not be a major project.No I am not saying the person at GM is wrong, but try those .535 you got and then judge what is better.