I bought a SSX tube for 870. When I screwed it into the gun, it was a little tight(yes, I put anti-seize grease on the threads). I shot about 20 rounds through it. Went to take it out to try a different tube and I couldn't turn it. I finally wrapped a rag around the tube and was able to turn it with a pair of pliers. After about 4-5 full turns I was barely able to turn it without using the pliers. I was worried that the threads on the gun were messed up. I put in a different tube and it screwed in with ease. When I got home I cleaned the threads on the SSX tube and the threads in the barrel. The threads on the tube look good with no visible damage(looked with a magnifying glass). After I cleaned them up I put it back in the gun. It turned easier, but not much. I was able turn it all the way in and all the way back out by hand, but it was tight. I emailed Tru-Glo, but haven't heard back from them yet.
Anybody else have this issue??