Lets face it, a reproduction is a reproduction. However it would be nice to get close to the real deal at least. Sticking a reproduction (or modern production) PU scope on a $100 infantry rifle doesn't really reproduce a sniper rifle, even if it has the bent bolt. The barrel is what matters most as the foundation of a good reproduction sniper, IMO. 70 years ago (+/-), when the mosins were in production, all the barrels were checked for accuracy, with the most accurate stamped with the sniper designation. Even if an infantry barrel is still in perfect condition, its not going to be more accurate now than it was then. So the first things I would look for are 1) sniper stamp on the barrel, and 2) that the barrel is still in great condition. Does anyone know if the reproduction snipers are created from ex-snipers?
Also, its worth noting that some people are under the mistaken impression that ex-snipers are identified by filled in holes in the receiver. That's only an indicator, not a foolproof identifier. The barrel must have one of the identifiying stamps aswell.