Get the biggest mold you can .
Trial and error , size the bullet as large as what ( when seated in the brass ) will chamber in your gun .
Work up from starting loads , watching for pressure signs .
God bless
Wyr
Get the biggest mold you can .I have a question on the size of a mold. I can get this mold in 432 or 434. It is a H&G #503 .44 Caliber Keith made by MiHec a custom mold maker.I have SBHs and I might get a Marlin down the road.If I get this mold in 434 would that be my best bet all the way around.I'm going to size for the SBHs right now @ 430-431. If I get it in 434 will I be talking to much of the bullet off @ 430-431? Thanks.