David E said:When the duty-size choice is 17 rds of 9mm, 15 rds of .40 or 10 rds of .45 GAP, most will pick one of the first two
Generally the duty size choice is a total of 18 of 9x19, 16 of .40 S&W or 14 of .45 ACP.
Models 17, 22 and 21 (or 21SF), respectively.
I guarantee there are a ton more Glock 21 and 21SF models in law enforcement hands, and civilian hands, than there are Glock 37s.