Thanks for those thoughts. Its an interesting calibre, when one would suspect the simplicity of its case and charge make it a dead cert for launching, but that is not the case it would seem.
The subsonic rounds seem to need a lot of power on some manufacturers actions such as Chiappa and certainly Ruger does for sure, to recycle the action in semi autos.
Very frustrating if you have multiple rabbits, and stoppages on the sub calibre round, when you consider the round was really designed specifically for that size of animal. Perhaps a proviso should have been applied to the box "Only for use with bolt action rifles"