Lyman 457121 BM

[Ron in PA]

Hi All Just picked up a Lyman 457121 BM mold. Can i use it in a Trapdoor Springfield. Thanks Ron

[John Allen]

Ron, I have used this same mold for the trapdoor. You will want to slug your trapdoor to see what the bore is. They usually run large. I pan lube mine.

[Doc Highwall]

Yes but it depends on what alloy you cast the bullets out of and what size the bullets come out of the mould with that alloy.

[Ron in PA]

Bore is 460, alloy 20 to 1.

[John Allen]

Ron, you might want to consider a hollow base mold. Lee makes one that I have used in the past for the oversize bores. I run the hollow base with soft lead and it works with the oversize bores.

[Wayne Smith]

Ron, cast a few and see what it runs. That is the gold standard. Each mold is individual.

[Ron in PA]

Thanks All, I have the Rapine 1881 500G its shoots very good, but the Lee 405HP does not. I'll go to the gold standard.

[Larry Gibson]

Ron

See what the "as cast" diameter is after you cast them. Are you using BP or smokeless? Cast them with 20-1 alloy or preferably 30-1 alloy for BP. A harder alloy such as COWWs +2 % tin is excellent with smokeless. I use that bullet in my TD for smokeless loads BTW.

Larry Gibson

[Ron in PA]

Larry, 65 gr. of 2f BP for the 1881. I'll try 23 Gr. of SR 4759 for the 457121