Since you just said 7MM and didn't list what the uses would be I will give what I think is probably the best all around caliber that most average shooters could handle well. It would have to be the 280 Remington. This is enough gun for all of the hoofed animals in North America. I wouldn't want to tackle the large bears with this caliber. The 280 is capable of firing controlled expansion bullets of 160-175 gr. that are strong enough for elk & moose. This point can be argued but for whitetail and mule deer this cartridge may be the best there is. Flat trajectory out to any sane distance and plenty of knock down energy to any sane distance.