practice with .22 handguns
Twenty five + years ago I was a law enforcement specialist in the security police in the ANG. At that time we were issued S&W 15s Combat Masterpiece Revolvers for handguns. We had some limited access to a nearby ARNG armory that had a 50 ft indoor range, but the backstop was of mild steel and we were limited to .22s and .38 wad cutters.
(I owned both a personal S&W 15 and it's .22 cal equivalent, the S&W 18. I also had an AR-15 and an Atchisson .22 converter. Shortly afterwards I bought a Colt Ace, which is the .22 cal equivalent of the M1911A1.)
Once and sometimes twice a month I'd go to the armory at 7am with the AR-15 with the .22 converter and my S&W 18 and shoot for an hour. A couple years later I did a tour in the local MP unit, and so I shot my Colt Ace instead of the revolver. Using the .22s was a good way to develop and maintain basic skills.
I still do a lot of shooting indoors in the winter with the .22s.
Out of the holster to first shot seems to be the best practice application for the .22 guns, in my opinion. I also like to do accuracy work at 50 feet on the NRA B-34 target, which is 1/2 scale, or on the NRA B-29 or NRA TQ-20 targets, which are 1/3rd scale. (Shooting at bigger targets with a .22 seems like cheating.)
(I just read in NEWSWEEK that the cost of copper has gone up 55% since January of 2006. With two wars going on, and the construction boom in China, world supplies of copper & other metals are stretched to the limit. I'm afraid the days of cheap "generic" ammo may be over, and I expect to be shooting my .22s a lot more in the future)