UMC 11 MM Mauser cartridge

[trooperdan]

Just "lucked" into a quantity of UMC loaded 11 MM Mauser ammo. I have no idea of the time frame when UMC was loading this caliber, what are the odds the primers would be mercuric?

I'd like to shoot them but I am more interested in saving the brass for reloading. Do you think I should break them down and punch out the primers instead of shooting them? I understand that mercuric primers didn't damage brass as much in the old BP loading as the amount of fouling diluted the primer effects and I "assume" these would be BP loads.

[Don McDowell]

Chances are pretty good those primers are dead. Also a real good chance they are berdan primed. Lotsa luck reloading those. No telling if that brass would come apart if you did get them to fire. Might breaks one down document the powder , wads and bullet and save the rest for posterity.

[w30wcf]

trooperdan,
Most definitely the primers are mercuric and, as Don indicated, dead. If you want to save the brass for reloading, the best thing to do is to pull the bullets, remove the powder and primer then clean and anneal the brass.

They do show other types of .43 / 11mm cartridges using berdan primers.

The 1906 UMC catalog shows the 11mm Mauser using their 2 1/2 boxer primer. I don't know about the 11mm Mauser but UMC 44-40 cartridges I have dissected have a slightly raised section around the flash hole. That was to prevent the reloader from using any primers other than UMC. I used a primer pocket tool to remove the raised section so that I could reload those cases with current primers.

w30wcf