RE: Buying new scope for 7mm mag.
I would get a Bushnell 3200 Elite Fast focus. I have one on one of my 25-06 and is very clear. Also another great feature is the rain guard which makes it clearer in rain or if you breath on your scope. They are also fairly cheapv I got mine for $180.
I wouldn't get a leupold Rifleman scope they are junk[:'(]
Good luck