I was a little hesitant to purchase these mounts as the feedback was either very good or quite bad. I took the chance as I really didn't want to replace the entire receiver on my crosman 1322 to mount a scope.I found that the mounts tighten down just fine. No stripping or slipping.I suspect the issue folks have had may center more around the fact that the crosman mounts are 3/8" which will not allow a standard 1" ring to securely fasten on to the mount. I had to purchase new rings that convert from the 1" tube down to the 3/8" rail mount.Using these new rings allowed me to securely fasten both the mounts to the barrel and the scope to the mounts. I have fired over 100 pellets at full power and the scope hasn't budged.Maybe other folks had different issues with tightening but everythiing worked fine for me. I would recomment buying the mounts.