I think it would be great to have separate magazines for pistols, SMG/AR and Rifle/Sniper Rifle.
Like:
Pistol Magazine, Pistol Piercing Magazine, Pistol Uranium Magazine. 10 bullets in each.
Firearm Magazine, Piercing Rounds Magazine, Uranium Rounds Magazine. 30 bullets in each.
Rifle Magazine, Rifle Piercing Magazine, Rifle Uranium Magazine. 5 bullets in each.
This also can greatly help with balancing your other mod - Tracer Ammunition, by making separate range values for each magazine type :)
