View Full Version : GP 100 Cast Bullet Diameter

07-03-2008, 01:39 AM

I am new to bullet casting. I have been casting for my SRH .44 with great success, so now I am hooked.

I have just bought a GP 100 and would like to know if any of you have any favorite bullet molds for this gun. I would also like any information on what sizing dia. I should start with etc. Basically, any information you are willing to share would be greatly appreciated. I am looking for loads for accuracy mostly. Thanks in advance.

07-18-2008, 03:32 AM
About 160gr lead, Unique or similar powder, with loads for 1000/1100fps (~6.5grs in 357 brass); 38+P loads with same powders work very well too.

I would try as-cast first. GP100 seem to be fairly tight around 357, but a bigger bullet will give better neck tension so you won't work the brass with repeated crimpings.
I hardly crimped with mine, for 357 homecast or 358 commercial bullets, but neck tension will depend on your dies.


07-19-2008, 11:00 PM
stick your calipers n the cylinder throats all of them and measure them
at least .001 over that is good bigger is better.
i shoot a 41 that i dont size in my black-hawk. just lube and load and give a bit of a squeeze with another size die to get them to load.