I have successfully shot three turkeys with a handgun. One in Alabama, and two inside a preserve.
I shot the turkey with the .357 in the center of the body broadside at 25 yards. Like most people, I expected a .357 to boil feathers and hammer the bird. I was wrong. Hit in one wing and across the top of the drumsticks, the bird was unable to fly or run. The turkey "swam" away; using its wings to breaststroke through the woods. I ran him down and finished him with a bullet to the head.
I thought the fast stepping and volitile .327 would be a great choice for a turkey gun. My first shot struck the bird off center in the neck where the feathers stop. A caliber hole through his neck didn't seem to affect him. In fact, I thought I missed. Shot number two passed through the body above and in front of the wing joint. Again the bird showed no reaction,he just kept walking. A third shot to the head dropped the bird. All three shots were taken at about 70 yards.
Mystified by the ineffectiveness of pistol calibers on body shots, I prepared my 22 Mag for a headshot. A 22 Mag would surely be immediately effective against a turkey head, right? Nope. Off center hits to the neck don't work. I started the shooting at 100 yards, striking the bird in the neck and throat. The bird went down, but I had to close the distance to 25 yards to finish the job. Five shots were fired with three striking the neck, but only the last struck a vertebrae and got the results I wanted. When I hefted the bird by his feet, he rained blood like a sprinkler from his head and neck.
I am still dissatisfied with my shooting results on handgun turkeys. I haven't figured out where or how to hit them. Conventional handgun bullets didn't upset on turkey flesh, and a bullet needed to stike the brain or spine to work as a headshot. I am thinking a handgun bullet needs to be fast and violent to work on a turkey body shot.