try shooting the CB LONG ammo. Its a standard .22 slug with a reduced powder charge. Very quiet and extremely deadly. I doubt they will cycle a semi auto. I shoot them in my old JC HIGGENS single shot. They will do a number on crows and any other pests you may have lurking around. Just remember that they will fly a long ways-similar to a short-so be aware!
P.S.-They work really well on certain pesky sea mammals!!!!!!