I've got a huge scope on my 7mm rem mag. Off the top of my head, its variable up to 18x or something crazy. The odd thing is, I never crank it over 9 power. A 3 x 9 is a perfect scope but a 4 x 12 will give you just a bit more if you need it. I'm actually in the market for a new scope and I plan on getting a 3 x 9 for a .308.