medved11 71 Posted May 18, 2016 I'm hoping that you guys can help me out with a issue that I'm having with a Wilson Combat 2 round extension that doesn't want to screw onto my 870 Express before I decide to send it back to Midway USA. I removed the factory cap from the magazine tub and tried to screw on the extension but could only get it to catch one or two threads before it wouldn't turn any further. I took a look at the threads inside the extension and they look fine as do the threads on on magazine tube itself (I don't see any burrs or easily detectable deformations in the threads). I tried screwing it on with and without the barrel attached to check if the barrel was interfering at all with the same results I ran over to a friend who has 11-87 to see if it would screw on okay and it did (with and without the barrel being attached). I was also able to screw on his factory cap to the 870 all the way down to the end of the threads (I've got no issues with getting my own factory cap screwed down all of the way either). Does anyone have any ideas what's going on here? I seemed to have narrowed the issue down to the threads on my 870 but I don't see anything obvious. I thought about putting a die on and chasing the treads but from what I've been able to find on the web, there isn't a die that will fit. Any advice would be greatly appreciated Quote Share this post Link to post Share on other sites
DonG 0 Posted May 18, 2016 I would check your tube with a micrometer, and your friends tube with the same to see if yours is expanded in size. Sound like its the actual width of the tube. Good luck with the fix!! Quote Share this post Link to post Share on other sites
medved11 71 Posted May 18, 2016 I would check your tube with a micrometer, and your friends tube with the same to see if yours is expanded in size. Sound like its the actual width of the tube. Good luck with the fix!! Thanks, I'll give that a try tonight. I'm guessing that there's not much I can do if my tube it outside the diameter of the extension? Quote Share this post Link to post Share on other sites