if you don't take it to a gunsmith (which is highly recommended) then i would treat it as a tree gun! use some padding to put between the gun and the tree so you don't scratch it. then lash it to a tree and point it in a safe direction into a back drop then, tie a long string to the trigger. stand way back and let it fly. then inspect the gun. i've done this a few times with old guns and only had one gun that came back with an issue, one of the shotgun i shot had a small breach in the chamber and the projectile only made it 3/4 of the barrel before stopping. i'm glad i had it on the tree because where it gassed out would have been in my face. this was on a shotgun that was hand made in Belgium about 1864 so this was a very old gun. i would still take it to a gunsmith though, just sharing my experience.