Boolit Sizing Micro Groove Barrel

[GregLaROCHE]

Hello Everyone,

I’ve cast some 405gr boolits for my Marlin .45-70 Micro Groove barrel from the 1980’s. Should I size it to .458 or add .001?

Thanks

[lotech]

I had one of the Marlin .45-70s from about the mid-'80s. Use the fattest bullet that will permit a loaded cartridge to chamber without difficulty. I think that was either .459" or .460" for my rifle.

[Walter Laich]

lotech is right

you want it to be tight all the way around once it's fired

will reduce/eliminate leading too