Are you talking a 7mm Rem Mag, 7mm 08, 7x57 Mauser? Either way for a big game rifle many hunters like to sight in at 2 to 3 inches high of center at 100 yrds. That allows you (depending on your bullet drop) a point-blank-range out to about 300 or more yards in that 7mm.
I shoot a 7mag for all my big game hunting. A Rem 700 with a 3-9 Leupold and 150 gr. Nos Ballistic Tips.. I zero 2-3 inches high @ 100 yards, gereally 3 inches high. Hold dead on your deer, elk, lope or what ever and DON"T HOLD OVER UNLESS ITS PAST 400 plus YARDS. The biggest mistake I see hunters do is misjudge distance and shoot over the animals back. How ever tempting put the first shot dead nuts on the animal. Realize that the kill zone of a deer is large and gives you some plus or minus in elevation by a few inches. Best of Luck.
Remember it's just A way, NOT THE WAY.
If you're lucky enough to be on private land and can leave your stand up during the off season you can tie an old piece of cloth or something of the sort to your stand. I like to use an old camo bandana that I have. That way the deer get used to the movement and eventually don't bother even looking up when there is slight movement. This may just give you the time to draw your bow or raise your gun without being detected.