Shotgun tube caps comes loose routinely

[HRnightmare]

My 12GA tube cap routinely comes loose after about 15 rounds. What do I do to fix it?

I was thinking about rubbing a light coat of removable loctite on the threads. Any suggestions?

 

[oneounceload]

White teflon tape might work if grease doesn't

 

[AI&P Tactical]

What model? I ask because different models and makes have different magazine cap retaining systems. If it is a Remington then you may have lost the detent plunger in the barrel ring. An easy fix is a "Wave Washer" from Wilson Combat. It will keep the magazine cap in place until you want to remove it.

 

[Virginian]

Put an O ring under it. Doesn't require biting into the metal like a washer. Cheaper too.