Both options sound like good deals...but if I were you, I would buy the used 7mm mag. You can definitely handle the recoil if you shoot 3.5 inch 12 gauge loads...just make sure you get a scope with enough eye relief. Ultimately it is up to you, and I doubt you will be disappointed either way, but just imagine the other cool stuff you could buy with the money you save. Good luck, and let us know what you decide on.

Rob