Funny you should ask:
I was at the Gun Show today and bought an Advantage Arms 22LR Conversion for my Glock 20 from Glock Doctor (aka Desert Scorpion). It came with the mag and a cleaning kit consisting of round patches, BreakFree CLP, rod, and attachments. The conversion itself consists of a lightweight upper with barrel, spring, rod, adjustable sights, etc.
I took it to the range after leaving the Gun Show and without cleaning or lubricating it. I put a hundred rounds of cheapo no-name brand ammo (from the gun show) through it.
At first, maybe because it was brand new and needed some breaking in, or maybe because there was no lube whatsoever, it would fire but not cycle. Fortunately, that only lasted a few rounds. After that, it was pretty reliable with the occasional ftf/fte.
I bought the conversion upper because I am recovering from a broken shoulder and have not been able to shoot for the last three months. I figured that starting with a .22 was a good way to ease back into things. I was right. It was a lot of fun! I am surgically accurate with it. There is NO recoil. And it is UBER inexpensive. $14 for 500 rounds.
If you have been considering getting one of these conversion kits, I would highly recommend it for the range. Not something you want to use to defend your life, but lots of inexpensive fun at the range. I am sure my wife would like using it as well, and when my kid gets old enough, it will be a great way to introduce him to pistols.
