RE: First big game rifle
The 280 would be a good choice as well. With Barnes bullets in the 30-06 you have the option of using the 250 grain Original. In 7MM the have a 195 grain bullet as well. The 308 bullet has a little higher SD. at 376 vs 347 if I remember right. The 45-70 would be a great choice as long as the range is not to long.