My neighbor bought this for $250 from a pawn shop. I am by no means an expert on any thing and need a little help identifying it. I thought it was a sporterized Nagant or a variant of. Can anyone identify specifically ? THe ammo looks like 7.62 X 54R . He got a bag of ammo with the sale and it shot fine until he loaded a 30-30 cartridge that was mixed in with the othe and the brass split while firing and he got peppered in the face with hot gas. I suggested he take it to a qualified gunsmith to ensure everything was still OK with it.Thanks for the help in advance.