The 30.06 Spr. cartridge incoporates a 30 caliber bullet. It is a pet pieve of mine to see a cartridge described as a "caliber". I'll get over it . This is a superb choice. The cartridge is a 100+ year old design that has proven itself in the military, shooting competitions and certainly in the field. It will handle an extraordinary range of bullet weights.

Most rifles that I have shot that were chambered for the 30.06 Spr. grouped exceptionally well with bullets in the 165-180 gr. weight. This of course depends entirely upon what your Ruger American will "like".

I know nothing about this particular rifle design other than seeing it at my favorite hunting/fiahin' store. The Model 77 line has been a very well built and well reviewed rifle design for decades. I suspect that the American will do just fine.

If you are going to scope the rifle, take a piece of advice from one who has "been there and done that" ..... don;t scrimp on the scope. Buy the absolute highest quality scope that you can afford. There are plenty of excellent scopes from which to chose and lots of truthful reviews out there to help you make up your mind.