turkeys
Since you asked, I believe the .22 mag from a rifle is a bit marginal for turkeys and body shots, and even more so from a velocity challenged revolver. I grew up around a bunch of older turkey hunters who regularly rifle hunted turks in the fall w/ rifles and the optimal ctg was a .22 Hornet or .218 Bee. The .25-20 was also popular, but not as common, as the lever rifles that chambered it were not easily scoped. The .22 mag was always thought of as a poor second cousin as a turkey rifle by these grand old gents.
Since a revolver will have even less velocity than a rifle, I can only believe that the .22 Mag will be even less effective. I suppose w/ head shots only, you minimize the risk of cripples. But a turkeys head is very animated. Heck, I know guys that have missed a turkeys head under 30 yds w/ a shotgun. (me included) I'd think the temptation to plug one in the body would be hard to resist, especially after a few misses. And the results may not be to your liking.
Hey, I like .22Mag revlovers, I have a long barreled Single 6 and love it. Will a .22 mag kill a turkey, certainly? But there are better tools for the job.