I shot maxiballs out of my 45 and they shot OK but had much better accuracy with the 10mm 200 gr XTP and sabots. Out of my 50s I found that the Maxihunters shot better for me (275 gr) than the Maxiballs. This was out of the 1:40 and 1:28 barrels.
Because no one makes a Maxihunter mould, I've been shooting 320 gr REAL bullets out of my GPH flinter with very good results.