Over the years, I've owned a number of original .50-70 rifles (trapdoors, rolling blocks), and shoot them.
BUT...
The groove diameters are all over the map - on the large side. Whereas the nominal groove diameter (and bullet diameter) is .515", I've owned rifles with measured groove diameters up to .522" or so.
I'm a believer in using bullets of full groove diameter in every case, but it is difficult to find or make such bullets in this case. The two rifles I'm shooting currently are a U.S. Model 1871, which has a groove diameter of .5165", and an 1866 trapdoor which measures .518" across the grooves.
I have a 350 grain mold which will produce a bullet proper for the 1871, and which shoots very well, but have been unable to find anything which will produce a bullet large enough for the trapdoor.
So... what I want is a mold which will cast a bullet of ca. 400 grains with a diameter of
.520" as-cast. I've been unable to find such a mold so far. Any help in that direction will be appreciated.
mhb - Mike