Hello,
Mine slugged .4575
It shoots jacketed and cast equally well. It especially likes Remington 405 JSP over 45gr Varget. I also have good luck with my own cast 405gr and 340gr out of Lee RNFP molds. They drop from the mold at .4585-.459 with straight air cooled wheel weights. They are tumble lubed with Lee liquid Alox and I get no leading at all. The charge for both is 31gr of H4198.
My BC is the most fun gun that I own and people at the club always want to shoot it. Hope this helps.