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.
I must admit that I have missed a big game animal with a rifle. And not only was it a bull elk, it was the largest bull that I have had in my sights with a tag in my hand. But, as with most "missed shot" stories, I have an excuse. Moisture doesn't really ever bode well for hunting equipment. When moisture (either rain or snow) gets into a firearms barrel, nothing good takes place. A couple rain drops down there can change the point of impact drastically and a barrel jammed with snow after a...