I use 28grs AA-5744 for my 500gr cast loads in my 458 Lott.I thought I had time to go and shoot a bunch today but next time.I shoot offhand with open sights always and at 50yds out of my Ruger.The last couple of years I shot them out of my CZ 458WM.That shooting was fun and then my barrel stopped shooting.There is nothing like shooting the big bores offhand and with reduced loads.A double rifle would be more fun but too expensive to rebarrel.I am looking forward to start shooting more often and attending the Libby Safari challenge next year.