Cpt Curl as promised here is the posts on NfB loads int he 577/450.
Nitro for Black Martini loads

Smokeless loads and compressed filler

And just in case this gets lost because in the last post on the first page....

First a word of caution about brass shotgun cases.They can be used, but read this without fail before you use a brass shotgun case.

Word of caution about balloon head cases