Hi-cap? H&K Mk23. If I need more than that, I'm thinking an old M3 Grease Gun (anything beyond that, it's time for a rifle round.)
M3 You have to be kidding me. The only way you gonna shoot someone with the M3 is they run in front of the bullet.
Not so - my granddad has an SA only grease gun that he'd built, and it was actually rather accurate (coffee saucer at ~40y, dinner plate @~100y. onsidering the bullet being thrown, that's actually pretty good.) Yeah, the M3 "as issued" is better used for "accuracy by volume" and you'd pull your hits based on the Law of Averages, but by the time I need that much ammo I'm stating to think either an M4 with a Beta-C or a belt-fed something-or-other (M1919 is good, M2 or M2HB preferred. M240 or M249 acceptable. M134 Minigun, anyone?)
Now, if you're going to hand any firearm to a newly-minted nugget, your assessment is spot-on - the safest place to stand around any new armed 2LT is directly in front of him - he'd never hit you.
Aircrew pants, Kris? Looks like a pocket for an ASEK on the upper left thigh and some extra calf cargo pockets - and issue BDU/ACU don't come with a zip fly, IIRC... I've been out a while, so it's sort of a mental exercise to me to catch up with all of this.