MK4M3's....v.s....MKm1's
Legionaire, for your purposes, a Mk4M1, or a LRT M1, will work fine.........
The M3's really shine when SPEED of shot is a prerequisite, they are not target scopes, they are military scopes...
And to answer your question, the MK4M3's, are 1 moa elevation, and 1/2 moa windage ONLY.
The MK4M1's, are 1/4 moa per click, both ele, and windage.
The MAIN advantage to the MK4M1's over the LRT M1's, is that you can (using a .308 cal), get by with using a flat non canted forward taper base.
You have 45 moa up, and 45 moa down.....when mounted flush, the 45 moa's is MORE than enough in .308, to get you farther than the caliber will shoot accurately.
The M1, LRT's.....usually require a 20 moa base, such as the Badger........either scope is a good deal, the Mk4M1, if you can afford it, is THE way to go, IF you want a fixed power scope.
For .308, I suggest the 10x..............
I have the M1's, and the M3's.....and I love em' both, but for real accuracythe 1/4' clicks are the way to go in my opinion.
fwiw...............