I cant find this ammo anywhere and Ive been looking for almost 2 days. Im not gonna start a new explosives character unless I know where to find them.

Ok so, Im starting to think this ammo doesnt even exist.

It definitely does. I got some from the vendotron at the GRs and some from Alexander at the 188. You're just unlucky with the loot tables, apparently. Keep trying.

Oh ok, thanks man. Ill head back to the 188.