With a 160 grain bullet, 3050 fps - 3100 fps is available, especially with your 26 inch barrel. Look to use the slower powders and work up carefully.

Unfortunately the 7mm Mag has some variation in chamber dimensions and so we need to be careful how to best handload. For this reason you'll note fairly conservative factory loads.

160 grain bullets at 3100 fps need some though, not sure standard bullets will always hold together at those speeds, especially up close. Consider premium bullets (should your application need it) anything over 400 lbs to my mind need premiums. Below that, normal bullets would be more than adequate. A good Speer, Nosler or Sierra BT at that speed shoots flat as and will give you amazing trajectory out to 400 meters.

Whichever way you look at it, that is a long way and probably further our than most of us should ever consider shooting. Pretty versatile the big 7mm.