[colt10mm]

Guy's what can you all tell me about 9x21 as opposed to 9mm, the reason
I'm asking is that Walther sells a 9x21 barrel for their P-88. It comes in a
9mm already.

 

[CCV]

No advantages unless you live in a country where the 9x19 is illegal for civilians to own. (Mexico, Italy, etc)

 

[WESHOOT2]

confirmed

Testing confirms no advantage.