I've read so much about chickens that peck at each other and ways of tending to the victims; the hand-made vest over the wound was way out there!
It makes more sense to me to deal with the overly aggressive chickens than to be doctoring a coop full of victims.
My peaceful flock enjoys a 4-sq.-ft-per-bird coop plus an outside "sun porch." They're 16 weeks old; I mix a 20% and 15% protein crumbles feed plus they get table scraps and "tons" of grass clippings.
A few weeks ago, I noticed one of the chickens pulling out feathers of other chickens as they went past. HUH?
Then, he flew up and attacked the foot of a chicken that was roosting comfortable--brought the chicken down off its roost. I knew it was just a matter of time before his sharp beak drew blood and I would have to tend to the victims of his crazed aggression. I went to my shop and sharpened the axe. Yeah, I SHARPENED THE AXE.
Before I turned on the water to boil, I thought, why not just cut that sharp point off his top beak so that he can't do any serious damage and see if he can live peacefully with the flock. I used a toe-nail clipper to clip the top beak back just short of the bottom beak. It bled a tiny bit, so I cauterized it. He went on to eat that same day with no problem.
The beak has since grown back to meet the bottom, but in a rounded shape. He's less lethal, and I sleep better. Remarkably, he's living peacefully in the flock.
I know this was a drastic measure, but it beats chopping off his head.
This is the first time I've ever had chickens that let me touch and hold them (yeah, feeding them as chicks from my hand). Because I can handle them, I do clip off the tips of their top beaks even with the bottom. I did that with canaries all the time; it was easier for them to pick up seeds! I do it with my chickens now. I don't think they need that pin-sharp upper beak--they don't have to kill rodents and tear apart carcasses.