My neighbors wife comes from a farm in a place called Devon ( not sure of the spelling) I have heard her complain long and loud about what she had to go through to own a shotgun back home. I hear it every time I haul a new gun back from the flea market or junk store with no paperwork hassels at all. She said the quickest way to drive some British government officials batsh*t would be to let them have a peek in any of my closets, gun vaults, or the walls in my place as more guns live in any of these places than she would have been allowed to own in 80 years had she remained in the UK, and some she would not have been allowed to own at all.
Sounds like you have a nice smoothbore, is it a cap lock or flinter? 777 substitute powder I have tried in the cap and ball revolvers and it worked OK, the smoke just didn't smell right, it will not work in the pan of a flinter very well. Once opened it will turn into a solid mass in less than a year if you have a lot of humidity so use it up and never leave it in a horn or flask. I am not going to say that it's great stuff, I sometimes have trouble getting BP and used the sub during a dry spell, but BP is what I like to use, just works best in the original style guns. 777 is probably better in the modern in lines that use shotgun primers to fire the charge.
