Up till recently, my Dept was pretty good about duty guns. You could carry a Dept issue gun if you wanted, or you could carry a personally owned gun within the following rules- no SAO, calibers 9mm/.38 up to .45, no magnums, reputable manufacturer subject to instructor approval. Issued duty guns have included Glock 17 late '80's to early '90's, S&W 5906 early '90's-late '90's and Beretta 92FS late '90's to about 2 months ago. I chose to carry a personal gun and started out with a Sig P226 for the academy and for about a year, then switched to my G21 from about '93 to about 2 weeks ago.
A couple of months ago, we got a new Chief who is adamant about standardization. As a result, we got Gen4 G22 duty guns, which are going to be issued with no other choice. As one of the instructors, I qualified with mine about 2 weeks ago and started carrying it then. Everyone else will start as they qualify with them, probably in about a month or so.
Backup and off duty aren't issued and are personal preference. Mine have included a S&W M649, a Ruger SP101 and, for the past several years, a G26. Since we switched to the G22, I think I'm going to buy a Gen4 G27 when our income tax return comes back in Jan.
Yankee by birth,Rebel by choice!