My brother spent a good deal of $$ on a Rock Solid mount for his m31-90 Mosin Nagant to scope it the RIGHT way. $170 but it looks like a great piece of work and have 3 mounting screws + a new bolt casing with a bent handle to clear the scope. Not to bad of a price but we're going to attempt installing it once we get the shop cleaned up and figure out the best way to clamp the barrel so we can drill/tap the barrel. I will take some pictures of this as we go along.