Alot of good ideas. I like "PB Blaster" when things seize up. Best thing God ever created to free up frozen parts. Spray PB down barrel after plugging/taping shut 209 plug hole.Soak it for up to 24hrs. Use very light heat if really bad. If PB won't free it up - get your cuttin torch out! I have never tryed the teflon tape mentioned(will have to try it someday). I use a regular automotive type anti seize or a copper based high temp(2000 Deg)anti seize. I have never ever had a nipple,breech plug or any part for that matter freeze up after properly applying anti seize on threads. Buy it at automotive store, cheaper than anything gun shop will sell.

Bottom line is - If you don't use some type of compound or tape on threads of plug, your probably gonna have problems gettin it out.

Good Luck