they have some for .30AK, 223 AK, Ar-15, Mini-14, 1911, several other handguns. Survivalists need one in the worst way, cause it's just not feasible to lug around 2-3 firearms and a back pack, and few are skilled enough with a .22lr pistol to take small game with it.
Anything that you do to the "main" rifle is also done to the .22 unit, you see. Folding stock, ambi safety, scope, red dot optical sight, sound suppressor, luminous sight inserts, trigger job. Do all those things to ANOTHER rifle, and the costs are over $2000. So the $200 for a .22 unit is a bargain, guys.
Practice with a 1022 is not nearly as good, cause it aint got the same sights, "feel", trigger pull, mag release, safety lever, etc, as your fighting rifle has. Under lethal stress, you tend to do what you have practiced the most. 4c a shot for .22lr, 40c a shot for 223, which makes more sense for sub 75m snapshooting practice?
There's a 60 gr, 950 fps subsonic .22lr rd (loaded into .22 Short cases_) from Aquila that makes a .22 rifle hit a pretty fair 'lick". It will drop deer, men, hogs, cattle to 50 yds or so, with a brain hit, and with a 223 sound suppressor, it makes no more noise than a quiet handclap. If it were not for the noise that escapes the ejection port when the bolt cycles, it would be as quiet as a BB gun, and there ARE ways to lock shut that breech. L:-)