Originally posted by BBMW:
I think some of your assumptions are off. Look at the Wikipedia page for the P320. It's interesting. It has at least a partial list of institutional users, including military and police organizations.
A few militaries have adopted it, starting with the US, and including Canada, Australia and some smaller ones. It seems to be doing well in the international police market, including some national police forces. Domestically several major federal, state, and municipal police forces have adopted it. These include ICE, Dallas PD, Chicago PD, Tampa PD, Milwaukee PD, State Police in NV, DE, HI, OK, and VA. Add a good number of county Sheriff's departments. This adds up to a lot of guns. I'd say the institutional market is probably pushing million unit if it hasn't cracked it already.
You just aren't guessing hard enough.