I had the same issue with SSX in my 870. It didn't mess up the barrel, but I was very concerned when I need a pair of pliers to break it loose and turn 6-7 turns before I could finally turn it by hand....yes, I did use anti-seaze on the threads. I shot Long Breads 6's, HV 6's and XX Mag 6's. The HV's & XX's had very similar patterns and LB's were just plain terrible. I contacted TruGlo and they had me return the choke to the place I bought it. I was impressed with the patterns I got with it, but I'm very leary of putting another one in my gun.