[refermech]

The thing that makes that gun so effective is that it carries a 20 round magazine (pretty sure)

[Constitutions Grandchild]

“Another thread is saying he has at least one FN Five-Seven pistol.
The magazines for those hold 20 rounds, with one in the gun. Also, that gun has little recoil and is relatively easy for even a novice shooter to shoot fast. If he had 2 of them, that’s 42 rounds without reloading.”

I was told this earlier today by someone with far greater knowledge of the subject than I. Perhaps this will help.

[TalonDJ]

The thing that makes that gun so effective is that it carries a 20 round magazine (pretty sure)

Lots of guns hold 20 rounds or can fit magazines that do. Not that it matters much since anyone with decent training can swap out a 17 round magazine in a second.