If your're looking at the vanguard s2 i highly recommend the .257 weatherby magnum or a 25-06 in a different gun. Theyre a dream to shoot, they shoot flat, and are proven elk and mule deer slayers. The ammo can be a little expensive for the weatherby. I have a 7mm-08 and full power loads are on par with .308 loads, i can hardly tell the difference when shooting them. A 6.5 creedmore would be a good choice but its trajectory is different, at 300 yards the .257 will have dropped less but after 600 yards the 6.5 will be above it. If you're into handloading you can the load smaller denser barnes bullets and push them faster for devastating effects. I wish you great success.