Shooting a turkey in the body with a pellet rifle I consider to be the worst choice possible and highly discourage it. Turkeys are not hard to kill and can be easily taken with .177 caliber, personally I like the .22 cal. Have taken them up close and at extended distances with great success. Anything under 60 yards I'll take head shot, placing cross hair directly behind the eyeball. Anything beyond I choose to take a neck shot. A body shot usually ends up with a dead bird but too often the bird wont be recovered, given hours or a day and that bird will have died from the bacteria of the pellet wound. In such cases it would have been best to have chosen not to have shot.
Take the time to know your quarry, take the time to know your rifle, learn your calls and you can be a very successful and ethical hunter.
Emu, .30 chest shots will do the job but why, not your best choice. I know the birds don't stand still for long especially in the fall season, spring season is a different story and much more exciting! If you are needing a bigger target may I suggest the shot high between the shoulder blades when walking away. Take your time and choose your shot, this is one of the most exciting, rewarding animals (birds) to hunt with a pellet rifle! I no longer hunt with a shot gun.
May you enjoy the same pleasure, Enjoy!