The description I’ve read is a vintage Mauser. I wonder if it was sporterized and scoped. I know all of us snipers here on Aldeer can make a similar shot with iron sights, but a non-scope rifle, under intense pressure, over 100 yards, presumably without the ability to carefully tweak point of impact to ammo choice … neck shot?? I don’t know. I wonder if the rifle found was a planted diversion