Heard the Smith and Wesson M&P is out of contention (shame)
Glock 17/19 looks like a likely choice, the FBI just went to them.
The SIG 320 probably has an inside track (unless reliability comes into question during testing) for the same reason the Glocks might. The grip size can be adjusted for smaller/larger hands, improving accuracy and training.
M&P is good! with two spare mags, the round count is 51! Great if multiple threats are present.
KYPD
USMC MARSOC went with Glock 19.
I’m in for the Glock 19 (or 17) or the Sig P320 if reliability issues are not a problem.