Ed,
I didn't really care for the hollow base mold so I removed the base plug with a file, instant flat base bullet, and it shot better as a flat base. I get most of my molds from Accurate Molds, Tom will design and build a mold that will fit your rifle, and his craftsmanship is second to none. You might want to check out Big Lube Molds, they offer a 400 grain mold with huge lube grooves designed for black powder.

Greg