Plumber grade teflon tape (pink) with any of the ML breech plugor other anti seize greasehas worked well in a pinch. AKA when I couldn't get any CVA breech/nipple grease. However the CVA I just coat it on the thread by itself, finger tighten and check it every 10 shots or so...never had a stuck breech.

That was using 777 & Pyrodexloose powder charges BTW.