Well, Mister & I just butchered 4 more roos today (I had ordered McMurray's "All Heavies" special & got 25 heavy breed roos 20 weeks ago, they don't need to be done all at once) and I found a hatchet to use. It made the job feel a bit more evolved to sever the head with one neat stroke rather than yanking them off by hand. So maybe I can't justify the trip to Harbor Freight after all, hmmm, I'll have to think of some other excuse...
The traffic cone seems like a good idea for use as a killing cone, the ones I've seen advertised seem costly & it would be better to use some material you already have on hand.
But I thought the purpose of the cone was to hold the bird still so you could cut the jugular vein neatly & accurately. You wouldn't want the bird moving while using such a sharp knife for this rather delicate operation.
If I'm just beheading the birds I don't need them to hold their wings so still, esp. if I have a helper. We place their heads between 2 long screws on the chopping stump & hold it down with a stick. Someone else holds the legs which are already zip-tied together, and pulls to stretch the neck. Chop!
I saw a tip somewhere here to put a plastic milk crate over the beheaded bird to keep it from flapping all over the yard, a bucket or basin would work too. It really doesn't last too long, I don't feel the need to buy another piece of equipment just to keep them from flopping around for just those few minutes.
I hang the birds by their tied feet to an old metal porch-swing frame over a garbage can with a plastic liner. That neatly catches all the blood, also the feathers plucked right there, and I toss the heads, feet & guts in the bag too. So most of the mess is contained in the garbage bag, with just a little leftover feathers to rake & blood drops to hose away.
If I could sufficiently motivate someone else in the family to do this, I'd have them dig a deep hole by a tree and bury all that stuff for fertilizer. But no one is willing & this is already chore enough for me!