I was just at the Range with my Mosin 91/59, was shooting some com bloc surplus ammo. I noticed the brass (about 5 of 15) had a crack or two down the neck all the way down to where the case expands, there was also a little chip missing right off of the front of the shells. I have shot mabey 5 shots out of this rifle before this, with that green steel cased stuff and it didn't crack those. Is there a problem with this rifle, or is it just the ammo? Is it unsafe to shoot like this? I would rather not blow myself up.