Bret_T

I'm not worried about it. I have plenty of other 9mm that will work just fine. I'm very happy with the performance right now. Hopefully the stock will stay put.

I received the spring set from RTG Parts. The recoil spring is obviously stiffer and is a full 1.5" longer than the one that I received from Northridge. The other springs I received also appear to be new. I installed the RTG recoil spring and went shooting. I started with Remington UMC 115gr FMJ in semiauto mode. The rifle would shoot bursts of about 3 to 7 shots. I was thinking, what's going on? Perhaps I put the selector on auto, so I slid it over. It would shoot, but would continue shooting a few shots after I let off the trigger. Then it dawned on me. The low powered Remington UMC ammo coupled with the new spring was powerful enough to eject and feed, but not powerful enough to push the bolt back to where it would catch. I then tried some Magtech 115gr FMJ and it ran fine. I'm definitely pleased with the RTG Parts spring set and really appreciate the recommendation. I'll just have to remember not to shoot low power 9mm through the Sten.

My new recoil spring measures right at 9". I bought it from Northridge and it definitely appeared new. I just ordered the spring set from RTG Parts and will let y'all know if it solves the problem.

I already replaced my recoil spring with a new one. It might have helped some, but didn't solve the problem.

My Sten is having the same problem with the stock sliding off. It seems that the recoil allows the cap to go in just enough to release the stock. Note that my stock is not original to the Sten. The original owner lost it somehow. I'm definitely open to replacing it, but would prefer the loop type. Meanwhile, I'll give Homealone1's fix a try.