Whenever I visit Houston, I always get a kick out of the various sidearms I see . It sure beats the hell out of nothing but Glocks.
The last time I heard, HPD gave you the choices of..
Smith & Wesson Model M&P 500, .40 caliber
Glock Models 22, 22C, 23, or 23C, .40 caliber
Springfield Armory Model XD-40 Duty, .40 caliber
Sig-Sauer Model P229, DA/SA or DAK Versions, .40 caliber
Sig Sauer Model P226, DA/SA or DAK versions, .40 caliber
I think in some cases, you can use grandfathered pistols from
past rules if you continue to qualify with them, but not totally
sure about that. That was an older rule, but not sure if it's still the
case now. I think you can have backups if they are .38 or over.
But most all carry .40's as their primary carry pistols, and they buy
their own.
I remember a while back, maybe 4-5 years?? ago, I saw a Sergeant
directing traffic at an intersection not far from here, when the traffic
lights were out.. He was an older guy with some obvious rank.
He had a .40 on his hip, and also had a 1911 of some type across his
chest using some kind of shoulder rig. He was ready for the gang
bangers..

It's been ages since I saw any HPD officer carry a revolver.
But I remember back say in the late 60's, early 70's, when most carried
.38 and .357 mag revolvers, and the semi-auto's were the exception.
I remember several years ago, maybe 20?, I saw one carrying what I now
think was a black and stainless Sigma .40.
Was the first time I had ever seen a cop carrying a stainless slide pistol.
:/
Out of the present choices of .40's, I know a whole lot carry the Sig
Sauer's. Or they were the last I heard. I'm not sure if the M&P's are
becoming more common or not. Haven't really paid much attention lately.