Before spring turkey season starts it is a good idea to go to the range and pattern your shotgun. To get started you will need a extra full or turkey choke tube. A turkey choke has more constriction than a full choke. A choke tube can play a big role in how your shotgun will pattern. Each choke tube should have the constriction size information on the package. For instance I have two turkey chokes for a Remington 870 12ga. one is a TruGlo Bone Collector the dia. is .667 and the other is a H.S. Undertaker the dia. is .665. Both of these tubes patterned the best with Winchester #4 and Kent #5 in 3 inch and 3.5 inch shells. I tested other brands of ammo and shot size but they did not pass the test.
When getting started use a solid rest. Start at 40 yards because this should be the maximum distance to kill a turkey with a shotgun. At 40 yards there should be 100 pellets in a 10 inch circle. There should be plenty of shot pellets in the turkeys head and neck for a ethical kill. After getting a good pattern at 40 yards I will shoot a pattern at 30 yards then at 20. This will also show you how your gun is performing at different ranges.
If your shotgun has a bead sight and you have used several different brands of shells and shot size and it will not pattern, you might consider using adjustable rifle sights or a dot scope. There are several brands of sights and scopes on the market today for a shotgun. It is up to you to find what works best for you. I have not had any trouble with a bead sight but I decided to use a rifle sight this year. I went with TruGlo's Pro Series Magnum Gobble Dot rifle sights. This sight mounts on your vent rib and is easy to install. The windage and elevation adjustments are simple with the use of an allen wrench that is provided. The sight is fiber colors in front and rear.
After you have sighted in at the bench try a few shots at a target from a setting position with your gun propped on your knee. I would also consider wearing some of your hunting chothes while shooting to make sure your gun fits the same as if you were out in the field.
Always remember to be safe at the range. Keep your firearm unloaded until you are ready to shoot down range. Always keep the muzzle away from others. And don't forget your eye and ear protection.
After getting your turkey gun sighted in I would recomend not changing to different shot size or brand of ammo once you start hunting. You would not want to miss a old Gobbler because you changed to different shells.