M203 HE with a light carrier has one in the tube and you can pick one up from a box.
M203 HE with a heavy carrier gets one in the tube, one in a pouch and that is it.
What is the point in what is fundamentally a one-shot M203 exactly?
Proper solution to this problem found here:
https://forums.focus-home.com/topic/32555/ammo-capacity-needs-a-rework
Crappy solution - up the number of M203 rounds available to 1+2 no carrier, 1+3 light carrier and 1+4 heavy carrier.
Also it should be a choice between the M203 or a full-scale launcher, the reason I think all this got nerfed is because you could carry both and spam explosives like crazy.