Re: enough elevation?
totally depends on how much up you have left from your 100y zero, and what sort of loads you will shoot.
In the .308, you'll be wise to shoot the 175MK at 2,700 fps MV. That load will stay supersonic past 1,000y, and will need about 36MOA to get there.
If you'll use bullets with lower BC (ballistic coefficient), you will need to drive them faster.
Pick your bullet, chrono your preferred load or use a predicted velocity from a loading manual. Then input the data into one of the online ballistic software tools (several available, free), and see what the comeups will be.
Compare them to how much up you have left from your 100y zero, and there you go.
If you won't have enough, you can very effectively use mildots for holdover, if your reticle features them, or get a tapered base or adjustable scope rings (like the Burris Zee type with eccentric inserts).
it's not about need in the USA -- it's about WANT