[Bartlett]

I'm guessing they probably had about 12-20 mags each, so that's 360-600 rounds, some may have had more. If they had four ALICE ammo pouches, that's 3 in each I think so that's 12, then they probably maxed out in other pouches/pockets, like Twombly says in film (and in real event): "you're not gonna need that dude [NV], you might as well take dope and beer [ammo]"

so where they kept NV/waterbottle/rations/equipment, they may have put extra mags. In my webbing and uniform, I'd guess I can hold 23 mags in my webbing - 12 in ammo pouches, 3 in each utility pouch and about 5 in respirator pouch, then if I put ammo in the pockets of my combats I could hold another 8-11, so I think I could hold about 35 maximum, boy I can't wait until I'm in the army.

I'm not disagreeing with you entirely, but maybe a bit.
Oh here's another thing. In the battle at night, in the film Kurth says he's out of ammo and Eversmann gives him his last mag, but Kurth and Eversmann only say they are out in the morning eek: