I've been out around Globe for Coues. I, and one brother-in-law, were the eyes and direction givers (hand signals) for my other brother-in-law that lives out there. He took a nice 3x3 (western count) that year. Whew! Talk about a lot of work! He took that one with a 30-30 at 150 yds after a long spot and stalk. He now uses a 300 win. No doubt a 270 would be an excellent choice. I think a shot out to 250-300 yds is reasonable if, like GB said, you have your ducks in a row. Since you are/were in the military you are no doubt proficient in shooting. But if you have been able to take 2 with a bow, which is no small feat, then getting an opportunity under 250 yds should be a piece of cake. I think that I would sight in at 2" high and use a rangefinder as well.
Long