Thank you for the tips - when I examined the breech plug the first 2 or 3 threads were blackened but boy you'd think the whole thing was covered in fouling. It took the long handled socket wrench to get free. I will try breaking the seal regularly during a session. Maybe even remove the breech plug before the rifle cools and I take it home.
Wish I had some anti-sieze grease, I'll try at the auto shop. Every time I go there however and ask for something they ask me what it's for and whether it's car or firearm related (i usually don't get specific) they hand me something else. At least they're trying to be helpful.
Arctic, thanks for the hookup!
My latest ammo findings:
Walmart had 240 grain XTP in sabots for $12 for 30. That seems like a good deal to me. I bought one to test, might go back for more since buying the components might cost more after shipping.
Box of Pyrodex 50 gr pellets is $30 and 1 pound powder is $20. They didn't have blackhorn.