This has been an ongoing frustration of mine for a while.

According to Wikipedia (not the most reliable source but good enough to demonstrate "public perception") Lyudmila Pavlichenko is credited with 309 "confirmed" kills and Simo Häyhä with "over 500". But how can anyone confirm or deny these numbers? I imagine that these sniper kills must have been self-reported, a sniper's job necessarily often placing them in solitary positions, so who could verify their claims? What would prevent ambitious sharpshooters from claiming incredible and unverifiable kill counts? Not only that, but how can we expect such claims to be true when they are so obviously useful to (and instrumentalized by) the propaganda machines of their respective nations? After all, Pavlichenko became a Red Army propagandist after recovering from a mortar shell impact.

I have found several articles discussing the lack of credibility of the achievements of Pavlichenko (which some attribute to sexism) and Vasily Zaytsev (mostly because his famous Stalingrad sniper duel is verifiably fiction), but so far, after many hours of searching, I have found nothing for people such as Häyhä or "White Feather" Carlos Hathcock. Does this mean that some snipers are considered more "legitimate" than others in their achievements?

Of course, I imagine that there must be at least some truth to all of these stories of "super snipers", but where does truth end and fiction begin? Is it even possible to tell? How can historians (or in my case interested amateurs) go about trying to determine how much of one of these legends is factual?