That's exactly what they were designed for - the .mil ammo. They work well with 55gr, to the limits of the 55gr max distance, but were really designed for the 62gr M855 ammo. It'll work for you, just zero the thing for 50 yards, and you're pretty much point/aim/hold out to 300 on a man-size or deer-size target. Just about the same vital zone area on both (7-ish inches).
I don't see difference in 55gr ammo until 450 yards. I can pretty much hold the same as my 75gr loads to 400. Running the 55gr to 450 yards, I have to hold for 500 yards to make hits. After 400 is where it really differs from the heavier projectiles, and where the 55gr drops off. The .mil 62gr is a weird animal, because of it's construction (the SS109/M855 loads). They fly like 75/77gr loads to about 600. After that, they drop off like the 55gr loads do after 400. Anyone that can run a 62gr SS109 to 800 yards is a badass. 75s and 77s get there easily, but the magic in those 75s and 77s is getting them to 2750fps muzzle velocity - that's when the magic happens - at or north of 2750fps on them...
Some of the SS109 is about 3100 fps, and the 55gr M193 loads are getting near 3300 fps. Both those loads are screamers, for what they are.