Leaky Breech Plug

[Duhawki]

My SMI 50 cal has made two trips to the range so far. between those trips, I did not remove the breech plug. Before the first trip it was tightened to a modest torque; I would estimate 30 ft-lbs. On the second range trip there was noticeable leakage / escaping gas around the plug. The barrel was totally filthy after the second trip and I did a thorough cleaning with the plug removed. The plug came out with probably less than 5 ft-lbs. Prior to assembly, I had lubricated it with Super Lube. When I took it apart, I noticed that it seemed to have a sloppy fit in the 9/16-18 threaded hole. It's measured size would categorize it as slightly looser than 1A. Is this normal? The good news is that the fit gives plenty of room for teflon tape which is in it now. I did torque the daylights out of it with the barrel in my vise when I put it back together.

 

[dwhunter]

I always tighten down snug then give the wrench handle two to three hard bumps with the palm of my hand. As long as you have anti-seize on the plug ther won't be a problem getting it out or gas seepage.