.22 conversion units
This is a topic near and dear to my heart. I started shooting .22 conversion units about 25 years ago, when I was a poor student. About the same time Jerry Usher had an article in (I think) the American Handgunner ANNUAL advocating the use of what he called "understudy" guns for economical practice.
During my military service I used an M-16 (three different models, actually) and carried (in order) an S&W 15 revolver, an M1911A1 and then an M9. I have personal examples of all of those guns.
Over the years I acquired a S&W 18 (.22 cal combat masterpiece), a Colt Ace (.22 on the o frame) and a Ciener and then later a Beretta conversion unit for the M9. And a Ciener and then a Colt conversion unit for the AR-15.
(I also have a S&W 650 in .22 to go with my S&W 60 HB 3 inch, and an argentine .22 conversion unit for my Browning P35). Back in the 80s we had access to the 50 foot indoor range at the local ARNG armory, which had a mild steel backstop and was limited to .22s. Shot thousands of rounds in there, and at the ROTC range on campus (I was enlisted, but I had a friend who was in the ROTC and he was able to get me in a few times) which was also limited to .22 because of a soft steel backstop and questionable ventilation . . .
I've done LOTS of shooting with all of them. I find it works best to do accuracy drills with the .22s. They don't have much recoil, but the balance and trigger pull and sight picture are all the same. For practice with the bigger guns I usually use an IPSC or IDPA target or an NRA B-34 (1/2 scale) target. For the .22s I usually use a B-34 or a B-29 or TQ-20 (both 1/3rd scale). I basically do my same set of drills at the same distances, but on a much smaller target. It helps a LOT to keep in tune and not spend as much money doing it.
The Ciener unit for the Beretta M9 is servicable. The Beretta factory unit works better, and does have a hammer decocker/safety, just like the original.
The Ciener unit for the Glock is marginally reliable. Mine worked better after I had the chamber and the sides of the extractor where it pivots in the frame polished. If I clean it every 150 rounds or so, use good quality ammo and lube it well, it works reasonably well. But not great. I don't have any personal experience with the Advantage Arms conversion units, but they're supposed to be much better.
I bought my conversion for the AR-15 in 1982 from Bro-Caliber International in Cincinnati. It was very rough and didn't work very well. Based on a 1985 article in SOLDIER OF FORTUNE I sent my conversion unit off to John Norrell Arms (now in Little Rock, Arkansas) and paid him almost $300 to tune it up so it would work. IT WAS MONEY WELL SPENT! As long as I keep the unit reasonably clean and well lubed and use good ammo, it'll shoot all day every day. (www,johnnorrellarms.com) (I don't know if he still adjusts conversion units like that or not . . . )
I also have a Ciener converter for an AK-47 and an H&K factory converter for the model 91.
Of course, the S&W .22 revolvers are a joy to shoot. Particularly the model 18.
The Argentine conversion unit for the Browning HP is pretty good as well. Like all the rest, kept clean, lubed well and fed good quality ammo, it shoots fairly reliably. (I bought mine from Sportsman's Guide about 5 years ago. There was another importer as well, but I haven't seen them advertised for quite a while now)
Peter Stahl in Germany also made conversion units for the Sig P6 (M225) and various of the Smith & Wesson auto pistols. I'm not sure they were ever imported into the US in any numbers. I tried to order a .22 conversion for my S&W 39 about 20 years ago but was unsuccessful.
Once in a while some importer will have a batch of .22 converters for the P38 pistol. I've never seen one and have no idea how well they work.
