I don't really think I will add different grenades for the launchers.
Just had another random idea. What if it was 1 item, but in some way you could make it change modes so it uses both types? Just like alot of weapons use grenade launcher mounts on rifles. But instead you press a button, maybe the light key, and the launcher reloads and it has the other gas grenade type. Then maybe some kind of indicator. Maybe text somewhere saying what type or that you changed types.
Probably the worst idea yet, and probably impossible. But it would be pretty cool. And if it were me I couldn't decide on which single nade type for it to use. But I'm not you so whatevs :P
Also. Lul@ me putting new ideas in every post I put in here.