The Quiet-22 uses a 40 grain round nose bullet and creeps along at only 710 fps. This cartridge will function perfectly fine in any single shot or bolt action gun. According to CCI, the round will also perform well in semi-auto firearms, though manual cycling may be required due to the low velocity.
CCI, you have my attention. I’d really like to get me some of this stuff. I shoot a semi-auto Remington 597, so if it doesnt jam up then I would have no problems working it like a bolt action if this stuff does what they are saying it will…. and as Richard points out, it would be amazing with a suppressed .22