Do I happen to have any ammo yet?
Well, I was thinking of giving you the ability to upgrade normal ammo into your special types, at the cost of a small delay (meaning you go last in the combat round).
As for you having ammo, nobody on the team would have been carrying ammo (Gilles' gun is an autocannon, much bigger rounds than .50), but you could have easily purchased some in the village, so I'll give you as much as you want (money shouldn't be an issue for basic stuff like supplies)
For total group carrying capacity, we'll assume 50kg max carry weight for Strength 0, and the multipliers are:
Raioyris - 2 -> 1.6x
Millenus - 1 -> 1.25x
Foreman - 1 -> 1.25x
Wilbur's stats are 0 3 6 0 (understatted, so Roseheart you should add 1 point somewhere. Took out the negatives because otherwise you'd be WAY under) (he wouldn't subtract from carrying cap. anyway if he had -1's)
Gilles - 5 -> about 5x (Unless the power armor gives extra strength. I'm assuming it basically nullifies its own weight in terms of strength, so no difference in total capacity.)
So about
500kg carrying capacity total. But if you carry more than 25kg you'll probably have to drop extra stuff in combat.
And 250 rounds of .50 BMG is about
30 kg. Which is enough to fire for 30 seconds. You'll need a lot if you want to rapid-fire (a Heavy Attack), which would cost about 5kg of ammo each shot. For single shots I won't be tracking ammo because that would be a much more efficient use of ammunition. Your energy charge attack is also a heavy attack but it would apply a much worse Status if you miss the constitution test. So there's that.
This also means Caellath may want to bring extra ammo. 5kg per Heavy Attack.
I don't think I'll stress over other supplies like food/water for now, because Butter is quite lightweight (1kg = 7000 calories) and even though butter is not representative of all types of food, ammo is much heavier in terms of how much you'll use in a day.
I do want to make carrying capacity a factor, though, because it determines how much you can haul up and might cause some interesting situations where there's too much loot to carry so you might want to leave someone to guard the stash from, say, other adventurers.