Dunno how "safe to say" it is, actually - given, say, the fact that explosive .44 rounds are such a rare loot that it's quite common to find less than a dozen of these from a full playthrough. I mean, that much is sure inadequate already, especially given existance of guns like the Tommy Gun, you know? So, maybe it'll be too few in the DLC, also. Happened once, can happen again.
Talking of which, explosive rounds + LMG / minigun should be a big thing about these new weapons - and contaminating 12.7, also. Both are extremely expensive to spray, but results vs non-robot foes should worth the price, me thinks. So, yeah, disassemble feat to get all the metal for ammo - i bet will become quite popular. Though getting enough casings would still be a grind - or at least, a major side activity (like using .44 sidearm as much as possible whenever it's not worth it to use the big gun).