LynnB, here's my take on turkeys. I think they ( eastern variety)are the most intelligent animal in the lower 48. I've taken more than my share, but it's been a process. The #1 best place to hit them for an instant kill shot on a broadside shot is a double wing butt hit. On a facing or going away shot is right at the base of the neck. Here's what's happened to me.
For long handguns: .223, 50 gr. Horn. SX. lost both.
6.5 JDJ, 120 gr. BT- taken 2 at 120 and 160 yds. Instant death.
6.5/.284 XP, 120 gr. BT. Jerked the shot (too low). Ran 75 yds. Lucky to find it.
.45-70, 400 gr. cast lead flat point. I "knew" this was the answer. Shot on a steep angle. Broke one wing butt and opposite leg. Watched him hop/half fly away. Bye,bye birdie. Never found it.
Revolvers: after the above fiascos I figured I'd finess them with my good ol' 6" Python that I'd killed 5 large ,nice bucks. Shot two (10 yds. and 50 yds.) with 158 gr. Sierra JHCs. Bye, bye birdies. No recovery.
.44 Mag, 240 gr. Sierra JHC (40 yds., 75 yds) Blew feathers every where. Bye, bye birdies.
180 gr. Sierra JHC, 160 yds. Actually dropped this one on the spot!
By now, every one is "saying" I'm not hitting them right. Well I learned to shoot a long time ago, but maybe you're right. I felt the sights on all the above losses were on double wing butts except the .45-70.
By this time I was extremely upset. I thought a while and came up with one LAST idea. I used my FA .454 Casull and the old Speer 260 HP. Too much gun? I thought maybe, but I had to try. Turkey #1, 40 yds., double wing butt, DOA. Maybe this was IT! Turkey # 2 thru #36 (20 to 140 yds.), all DOA, didn't move an inch. Bad damage? Nope. This bullet is meant for heavy duty work, so it's hard. Each bird had a 1- 1 1/2" circular area of damage in both wing butts. Absolutely 0 meat damage!
So, .357s for turkeys? I know some have done it, but on eastern turkeys??? Tread lightly if you do. Based on my "unscientific, uncontrolled studies, I'd say the best turkey revolver would be a large caliber, "hard" HP (that will give some shock effect", with decent velocity (1200 fps or more), put right on both wing butts.
Pardon my diarrhea of the keyboard, but I've become rather radical on this based on the above "data".