That M39 looks to be in fantastic shape based on the very few pictures. The chamber looks normal to me. What does the rest of the rifle look like. The M39 is the most accurate Mosin Nagant made, just make sure you shoot quality ammo (Hornady Vintage Match, S&B...etc) thru it before passing judgement. Russian made modern 7.62x54R is not very accurate IMO. What is the price on that one? What does it say on the barrelhood right in front of the reciever?
Here is a good link with info on the M39 as well as all MN from around the world: