I have an original and a repro.
The original was purchased from Wheaty. He rebuilt an original PU scope/mount and added it to a well used but all original sniper.
Looking at the outside of this thing, it looks like it was dragged for miles, through the mud, snow and gravel. The stock is beat to hell and there isn't a bit of blue left on any surfaces. It's saving grace, is an almost perfect bore.
It has the tell tale serial number on the left side of the chamber area. To my knowledge, all but some of the originals with PE scopes bore these numbers.
In all honesty, I can't find any discernable difference in accuracy between the original and the repro.
At 100m, even with the scopes, the snipers aren't any more accurate than open iron sights.
The difference really starts to show up around 150m-200m. The scoped rifles have the edge.
I have a repro, with the PE scope as well. The PE scope is definitely superior IMHO. The groups are noticeably better at all ranges.
At 200m, using the iron sights on four different rifles, original with PU, repro with PU, repro with PE and LS 91/30, with iron sights, they all shot into around 3 inches, with handloads.
From what I can find on the internet and the books on sniping that I have, the Russians didn't cherry pick or purpose build rifles as snipers. They were taken in batches, indescrimiantly off the assembly line. From what I can see though, all of the rifles I have, use the "high wall" receivers.
Once they were assembled into snipers, they had to pass an accuracy test, not before.
I wonder if the rifles that are being sold as "EX Snipers" that have the filled in mount holes on their receivers are really rejected snipers and not rifles that were sent back for regular infantry use after WWII, because they had to many??? They certainly don't have the extra set of numbers stamped into the left side of the barrel.
Again, from what I can gather and nothing definitive, they didn't get the extra set of serial numbers on the left side of the chamber, until the were passed as acceptable.
After this many years, who is alive that knows for sure anymore???
From one of the quotes of a factory manager, they had to supply thousands of sniper rifles on a steady basis. The quality control wasn't any different for the sniper than the standard issue infantry rifle. There just weren't enough resources or time to spare.
Anyone that has an accurate Model 91 or 91/30 knows how accurate a well maintained Mosin can be. The Finns, supposedly took it a step further. I can't prove that but I have a couple of Finns. The rebuilt SA barreled 91, is almost mint and shoots better than I can.
The Westinghouse, again SA marked, still wears its original barrel and although worn, shoots OK but isn't a tack driver by any means.