RE: Nikon which one?
The 2-7x32 is going to give a larger field of view than the 3-9x40. Seven power is way more than enough for deer hunting with a 7400. A couple of years ago I shot an antelope at 425 yards using a 2-7x32 monarch mounted on a .25-06. I also shot prairie dogs at 250 yards with the same rig.