my boyfriend made really nice killing cones for us, but they were a little too narrow to keep the chickens from flopping out. We simply made a noose out of baling twine with a cement block tied to it to slip around their necks and hold them down in there. It had the added benefit of keeping the head still while we shot them and then made it easier to slit the throat and ensure a good bleed out. The cones were mounted on a saw horse so all this happened at waist level or below, and it was very safe, of course you have to consider where you are, not everyone can shoot off .22's in their yard. I did some by just cutting their throats and that worked good as well, but it made me feel better knowing they had no brain left after being shot. Tied down tight they didn't flop around at all, just kicked their little leggys and bled out in a bucket, snipped their heads off releasing the noose and pulled them back out of the cone. plastic baling twine stayed cleaner than natural.