Feeding 10mm with heavy hard cast bullets with a flat nose/ogive can really become a problem depending on the cartridge overall length and the internal dimensions of the magazine. I'm curious if anyone has any Underwood 200 grain hard cast and HSM bear load 200 grain hard cast on hand to give me an accurate COAL for either/both.

Thanks in advance,

John

I just shot some 200gr hard cast through my 10mm. They were the Acme made 200gr hardcast. I seated mine to 1.260. I shoot a G20 I did the plunk test and made sure I could turn case freely as well. I was using 8.0gr of longshot with cci300 primer mixed brass. Oh also have kkm barrel in my G20.

I can measure some of the factory underwood for you later

I have to seat my Arsenal 195gr WFN hardcast bullets to 1.244" COAL so that they will feed in my SR1911-10.

Forgot about this , 1.246” average