This question came up here locally a while back. A gunsmith I know got a Remington 550-1 .22 auto rifle in for cleaning. This has a floating chamber to assist with cycling .22 shorts, longs and long rifles. When he cleaned it -- surprise, it would cycle with long CB's!
Naturally, the next one in the shop was cleaned and tried... but it was a no-go. It almost cycled, but not quite. A friend was interested in setting up a 10/22 to shoot long CB's semi-auto and researched it some. Vollquartsen's apparently makes a .22 Short adapter kit for 10/22's (costing about $200?) with an aluminum bolt and special mag. We were wondering if the aluminum bolt and a regular 10/22 mag would cycle with long CB's. However, my friend was not willing to bet 200 bucks that it would, so he went on to other daydreams. By the way, the longer the barrel, the quieter the Long CB's will be. In a typical 10/22, they are noticeably louder than in a 24" barrelled rifle, as per my tests. My quickie accuracy test in an old Winchester bolt action .22 with 24" barrel and 4X scope at 50 yards showed CCI Long CBs to give vertically strung groups of 2.58" to 3.44". (5-shot groups). In a Winchester 74 (.22LR, 24" barrel, I believe) chronographed velocity of CCI Long CB's was 642 fps with an extreme spread of velocity of 108 fps! A test using observers who could not tell which rifle was being fired, located 50 yards to the side of the shooter on flat ground, showed that the observer could tell no significant difference in the sound of a 24" barrelled bolt action firing CCI Long CB's vs. an Air Arms Pro Elite .22 spring-piston magnum air rifle (15 gr. pellet at 820 fps chronographed.) If anyone has info on .22 semi-autos other than a .22 Short Win. 74 that will reliably cycle with CB's, I'm all ears!! John