Okee:  you should be shooting .431 diameter bullets, not .432.  The larger slug will open up your groups.  I would measure them first to make certain they are .432 in diameter and if so, send them back and get .431s.  
I use Beartooth Bullets quite a bit in my 444s.  Two rifles prefers the .431 and the other the .432.  If I shoot the 432s in a a rifle that prefers the 431s the groups open up the same as if I had shot .430s through the rifles that prefer the .431s.  
My 44 magnum prefers the 430 cast and 429 or 430 jacketed.  Both jacketed slugs shoot equally well but if I use a 429 cast I get 'not so hot' groups - when I bump it up to 430 I get some pretty nice tight groups.