I've tried most powders including unique, bullseye, Rex 32, trailboss and more recently bluedot. The 265gn rcbs hollow base bullets are the only way to go. I've tried the 44lc projectiles with limited success
Best loads so far is 3.8gn trailboss. Primer wise I use winchester as they are hotter than others.
4.3 of unique also works ok but is very dirty.
Reloaders carry the .455 dies or you an use 45lc
Good luck with finding the grips. There are a couple of sources overseas which make copies if the hardened rubber origionals
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