#1). What problem does military brass present to the reloader. a). If "match brass" --none. Same as commercial. b). If "regular issue" then the primer is crimped to prevent backing out in a full auto and possibly jamming things up.
You can remove the crimp is several ways. For just a few, a pocket knife blade does fine. Once around leaves a bevel and takes out the brass squeezed over the primer. If weighing cases is important to you, many, many firms make a "swage" tool that will force the brass back without removing any and leave the bevel for the next primer. RCBS works within the press opening. I think it is CH (ch4d.com) that works above the press. As suggested, many just use the case mouth chamfer tool. Works good, but my fingers get tired after the first couple hundred. AND last, there is a "counter sink" for the flat head screws with the underside of the head tapered... chuck one of those into a drill, electric screwdriver, etc. and touch it to the pocket and the work is DONE. Sorry, I am not a carpenter and don't remember the exact numbers. I am sure the hardware stores will have a chart. Probably need 2, one for large, another for small.
#2). Many, many years ago, I think it was C. Audet, but it was a top competitive shooter with lots of machinist tools, did an evaluation of military brass, range run issue; military "match" brass; and "commercial brass." Article was printed in Am. Rifleman as I recall. His measurements found no appreciable difference between "commercial" and "military match" brass. I think he worked with .308 (sorry, 7.62 x 51 NATO), and .30/'06, very limited. Soldier issue brass was not nearly as precise. Much, much more "sloppy." I suppose it can be sorted, but more work. No big deal if you don't mind OR really want the savings.
b). Had a friend trained as a "gunner" / aircraft during WW II. Point he made to me, retired gunsmith too, the full auto barrel is not pointed at the same place each time a bullet leaves. Gunners are trained to think as if shooting "shotgun", i.e. "pattern." In brief, since the bullets will not be going into one hole, they don't worry about "precision." In fact, he suggested, the sloppy cases might contribute to this distribution...
#3). Is military brass better? Well. I had a cousin, decades ago, who lived near a military firing range. If the military was going to use it, the MP's came in and chased everyone out and set up road blocks. . Otherwise it was a "park" for the local population. Fired brass, fired bullets, etc. were left lay. His father filled his pocket with once fired .30/'06 and had a life time supply for his deer hunting. He had a kids collection of fired brass, bullets, bullet parts, etc. Boy was I jealous.
O.K. IF THE BRASS IS FREE...
Otherwise, if you have to pay... Your call. I don't mind in the least banging away at p'dogs with mil. surplus that might not be "match" accurate. If I have to shoot again, I shoot again. Helpful little furballs, at range, will look in the direction where the bullet passed by... But you pay, you call. LUCK.