New mag won't be abny better, and more than likely you'll have to adjust the feed lips on it as well. The assemblers at Savage adjust the lips of the magazines included with the rifle so they feed properly (or at least they are supposed to), but replacement magazines are "as delivered" and 9 times out of 10 will need some tweaking.

As for the rear sight issue, you might try looking into getting a slightly taller front sight to accomplish the same thing. Can't remember if they're screw-on or dovetailed as both of mine are heavy barrels with no sights, but a replacement for either should be fairly cheap. Check Williams, XS Sights, or some of the other common sight makers. IIRC Savage typically uses Williams sights on their centerfire rifles that have open sights, but the rimfires may be Marbles.