Guns that share ammo

Thought this was pretty cool, at least you can know what guns share ammo. Not that anybody really looks anyway.

7.62 round - M14, M21, G3, M40A03, R700

.45 round - M1911, USP

9mm round - M9, MP5, Mini-Uzi

5.56x45 - M16, M4, G36C

12 gauge - M1014, W1200

The same thing works with the noob tubes if you OverKill two assault rifles with tubes. You can shoot 4 grenades from one gun.

Wow, I wish I knew that before. That's awesome.

I knew what weapons used the same ammo just by general weapons knowledge. Except for the G3. Don't really know anything about that weapon.

Some strage things though. Why would they use the mm verion of the m5? And why would you use the same ammo for the auto shotty that the pump uses?

Odd..

What would you use different for the auto? 20 gauge?