I completely empathize with you, Jon. One of my poults broke his leg and I had to put him down. This is the first time I have had to kill a turkey.
Some 30 years ago I raised chickens for eggs. When the girls stopped laying efficiently, I dispatched them and got more. A friend that raised wolves to re-introduce into the wild here in Oregon would come over and help me. We just broke their necks and tossed them into garbage cans for transport. They do flop around a lot.
However, killing the 5 week old turkey was different. I tried breaking his neck, and probably did, but he did not act like he was dying/dead, even with his lolling head. Not just flopping; he was flapping and still breathing! I twisted his head again; it came partially off, squirting hot blood up my arm. He immediately stopped all movement. Ripped the guts out of me...
I will be taking a turkey butchering class next week.