1943 pu sniper

I own a Mosin Nagant PU Sniper , sn. rr xxx. The bore is well worn , however it shoots very well. Having owned it for quite some time , I noticed that the stock had been shortened by about 3cm. For use by a female sniper perhaps ? I had never noticed until it was compaired to another Nagant. Butt plate sn matches the rifle.

AFAIK the Russians didn't shorten stocks for anyone. That was wartime and you fit the rifle, not the other way around. Others will be along to provide more detail. Of course, pictures would greatly assist in the answers.