SAVAGE, not all Mosins are made equal, and on many (if not most) the rear sight is actually soldered to the barrel. Even if you drive out the pins (which wasn't too bad on my Mosin), the rear sight won't budge unless you put a blowtorch to it to melt the solder underneath. Apparently the heat can damage the rifle's bluing though, and I am not willing to subject my gun to such abuse. So instead I've been looking for a decent price for the Brass Stacker removable mount that goes over the rear sight. The upside is that it doesn't require a removal of the iron sights and allows the shooter to continue using them. The downside is, the scope ends up sitting quite high over the barrel, which may or may not be an issue. Most Brass Stacker users swear by it in their online reviews but unfortunately the price in Canada is ridiculously high (check out Amazon.ca).
The other issue with any mount that goes in place of or over the rear sights of a Mosin is that it requires a pistol scope to give you the proper eye relief. Because of the rifle's kick, however, many cheaper pistol scopes apparently don't hold zero very well on a Mosin, so to get a reliable scope you would have to shell out more money than you paid for the rifle itself. The price factor is the only reason I am still shooting my Mosin using its terrible iron sights.