There are few times on a military spec op or covert op where a operator could just; "buzz thru" someone with a MP5 or a Uzi.
They need to use all the available rounds to fight off any threats or bad guys.
If I were a SEAL or in SAD or ISA or ACE and saw a operator burning through SMG magazines, I highly doubt the dude would go "down range" any time soon.
I'd suggest reading Rogue Warrior, Red Cell, First SEAL, or maybe One Perfect Op. They explain how real spec ops & weapons work.
John Plaster(US Army Reserve-retired) wrote a few non fiction books about the MAC-V-SOG or Special Operations Group(also called Studies & Observations Group,
). They offer a in-depth look at how real special ops work in places like SE Asia.
You can't go "Winchester" with small arms on every target.
CF