I'm a 74 yo widow who has to handle/process turkeys by herself, and what a relief to find that I'm not the only one that got beat up by my heritage breed turkeys. No more. This is what I did:
http://www.apppa.org/Archive.htm Scroll down to the article for building your own killing cones and chicken transport boxes. There are pictures and complete instructions. I built the crate, but made it 24 inches tall, with a gate at one end and added another gate on a side so I didn't have to crawl in the thing to get a turkey at the other end. None on the top, since turkeys tend to go up in the air when spooked, and both gates are hinged at the top to swing upward when opened. It easily holds 6 adult heritage breed turkeys. Used some old lawn mower wheels to build a cart to go under it so I could pull the thing to where the feathers come off, instead of straining everything trying to carry it. (I do intend to build a chicken carrier too; just haven't gotten to it yet.)
My turkeys have been trained from the start to move away from me when I'm carrying a particular broom....the one with the bright yellow handle. You take your time, and you can herd them into a barrel ... (well, maybe not, but close). They're like range cattle....take your time, or deal with a stampede. Difference being that these critters can and do fly.
Late afternoon before the day they're being processed, a few more than I want are herded into the chicken coop. There's a covered, medium sized cattle panel/chicken wire covered pen built along one wall. They spend the night in there. Next morning, everything else is herded out of the coop. The main door is 4 feet wide x 8 feet tall. I have another half cattle panel, covered with chicken wire and a tarp, that fastens over that door; there is an opening at the bottom that is the exact size and shape of the cart and carrier, which is pulled into that opening and its end door swung upward. The only "opening" they can see access to is the door into the cart....the tarp shuts off the outside light above it....and they will almost always just walk into the opening because there is light coming through the sides and back of the cart and a partial view of the yard outside. Again, patience is needed....don't get turkeys riled 'cause it takes a while for them to get over it.
When loaded, close the cart door, fasten it, push it out of the cattle panel barricade, move the barricade and take them to the processing area. There, by raising the side door about a foot, I can reach in and grasp the legs of one of the birds and pull it out. By keeping its back against my legs, any flailing of wings is avoided, and the bird soon settles down.
The backyard chain link yard fence serves to hang the turkeys, one at a time, hung with their chests against the wire. I use a choke chain dog collar on the legs, and the top of the chain link wire was installed so it's about 2 inches above the horizontal support pipe. Two or 3 of those end wires serve nicely to hold the loop of the choke chain. Pithing and cutting the neck arteries happens quickly....the bird seldom moves since it is brain dead. Drop my knife on the ground, grab the end joints of both wings, bring them together behind the turkey (it is still facing the wire), and hold them securely with both hands (I have arthritis in both hands.) until the bird stops bleeding .... they will flail some just before dying, if you don't hold them.
From there, it's just dunk, pluck, and remove the innards, put in the cooling tank and go get another. I can easily take care of six by myself in one morning...not having to arm wrestle the buggers helps a lot.
Hope this helps. Can take some pictures if needed.