Do you mean without the barrelled action attached to the stock? Almost any barrelled action can be fired when removed from the stock, but because it is not intended to be used that way, it is not considered to be a pistol.
There are a couple of takedown .22s which you see frequently. There is the Marlin Papoose, and the AR-7. The Marlin is more conventional, basically their magazine fed .22 with a removable shorter barrel in an abbreviated stock. The AR-7 is purpose built, with a bulky plastic stock which holds the action and barrel when the unit is taken down.