Running shot down a rifled barrel of any length imparts spin to the shot wad. As soon as the wad and shot exit the barrel, centrifugal force opens the wad, slowing it down so the shot comes out. But the shot is spinning also, spreading rapidly. The shot in a .22 is really small and does not have much energy beyond 6-8' and it has spread so wide then that pattern density may not be effective.
IMO .22 shot cartridges are at best a novelty, especially when spun out of rifling.
If you want, buy some (they are expensive) and pattern them from your gun at 5, 10 and 15 feet on paper. You may find a ring pattern with very little shot in the middle and more out on the edges because of CF.
From shotgunworld.com:
"when fireing .22 lr shotshells out of my little smith n' wesson model 22 with a 4" barrell, it has a very wide pattern of about 2 1/2 feet at 7 yards. i killed a copperhead with that pistol last year, so it works just fine for that purpose.
i have also fired the shells from remington, sears, and marlin rifles, and even with a longer barrell, the pattern is still pretty loose, but still tighter than with the pistol.
edit... i would stay away from the crimped shotshells. i bought some federal crimped 22 lr shotshells, and every one of those i fired jamed up really bad. the crimping opened up, and lodged the shell in pretty bad. also, the shot deforms really bad on the crimped shells, so the patterns will be even worse."