Ammunition Counter

I am thinking of doing the following but it will be laborious, as I created the field grenades, I will replicate the "ammunition" field for her to indicate how many grenades I have, but more than that I am thinking of doing as much for the grenades as well for long range weapons a link between the purchased quantity and the weapon.
Example:
If I buy two plasma grenades in my inventory appears 2 plasma grenades as well as the amount in the combat flap.
The same would happen with the ammunition of the weapon, but each comb of ammunition would add me the number of shots and every time this number of shots was reached the inventory comb would decrease, another thing I was thinking is when both numbers reached 0 , roll normally as in any ruleset, but the message I am missing ammunition ... these are just ideas, which I do not know if they are feasible or even applicable.