Cheap, overbuilt, and powerful. The 7.62x54R is roughly the equivalent of a 308 winchester.

The actions can be a bit clunky on some of them and the magazines are somewhat difficult to load without stripper clips.

They are not all equal.

Finn Mosins were usually captured from the Russians and were rearsenalled with a new barrel and stock. Finn built mosins are very accurate, but also cost in the realm of $200+

Russian mosinsrun the gamut of being completely worn out to being halfway decent shooters. A lot of them are on the market right now and are described as 'arsenal refinished to excellent condition'-most of these simply have the stock refinished or a new stock installed- always check bore condition.

The 91/30 and 1891 are Russian long rifles. M38s, M44s and M59s are russian carbines. In general, the full length rifles will be much better shooters than the carbines. The carbines will give you dismal to acceptable accuracy. I much prefer the full length rifles not to mention they tend to balance really nice for me.