midtennpawnstar- Mosin Nagants are beautiful rifles in that they are cheap, durable, and for the most part, reasonably accurate.
Barnaul, and Wolf make alot of steel cased 7.52x54R and have given me decent luck so far, also 440 round "spam cans" can be had for as low as 70 dollars, and depending on country of origin and bullet weight, will give great results.
One thing to keep in mind with surplus ammo is the corrosive primers, the mercuric salts must be neutralized with something like ammonia or Hoppes solvent after every use to avoid corrosion on the working surfaces.
They are all sighted in at the factory with the bayonet on, as it was standard Soviet practice, so you will get good groups, but not POA. The sight posts can be a bit stubborn, but they worked for a wartime so they will work for you. If that is not the case, Mojo sights make a great replacement option, that are no gunsmithing required, and relatively cheap.
There are many Mosin Nagant owners her and arount the internet that will be more than happy to provide model identification assistance, and aid you in breaking in and enjoying your rifle.