Nice find
I cant help but wonder just where it was 'loose'? If only when opened up, well, they are, and the forearm spacer tightness will affect that. But if it was loose at the standing breech then you need to shim the pivot (see the FAQs).
Trapdoor level loads will do all you need to and cast bullets with Trail Boss is a favorite.
BTW, I had a 44Mag Shikari 30ish years ago; should have kept it...........
Enjoy!