I shoot a .308 for accuracy, usually 600 yard ranges.
I seperate the head stamps.
I've found the '86 to current military brass to be consistent,
'86 back have different size flash holes...
There are both size flash holes in '86, probably the last of the production run before they switched.
Watch the case neck thickness.
Military uses a HARD crimp on the necks, so some cases need to be turned for thickness and trimmed to size before you put them in rotation.
All military primers are crimped,
And I have to say, the best way to get rid of that crimp is a UNIVERSAL decapping die,
Knock the primer out,
CUT the primer crimp off the case,
Then throw them in the tumbler with the rest of the cases.
INSIDE the case neck deburring tool works the best for me,
Power or epoxied into a handle for manual operation.
I've tried about every primer pocket (Compression) tool, and compressing (Forming) that work hardened brass is a CHORE that will have you yanking or pounding on press handles,
It's MUCH more simple to just trim the hardened lip off,
Leaves a nice taper to guide the new primer in,
And it's a ONE TIME job when you get a fresh batch of military cases.
As for cases, as long as the case VOLUME is the same,
(IE: Military Case Volume will sometimes differ from Civilian Case Volume)
You won't have any issues.
I know some guys think the QUALITY of the brass has something to do with things,
But it's the VOLUME/Air Space in the case that will cause a difference in loads,
Along with the flash hole size,
If the case volume and flash holes are consistent,
You will make consistent rounds.