I broke apart my 22 can about 4 months ago and cleaned it. Since then I have only put about 200 rounds through it but the end cap won't screw off now. I soaked in acetone overnight, nothing. I tried break free overnight, nothing, even liquid wrench. Will anything dissolve the carbon? I'm afraid to put the body in a vise even with padding. I also soaked my 308 can overnight and the solvent was still clean the next day. Very, very little sediment. Suggestions? Thanks