Hello
I'm shooting a Mossberg 535 with a xx choke and 3" # four shells. If I shoot this at 20 yards how many pellets in the vitals would be good to see?
If I am not getting good numbers in the vitals should I change the bullet or the choke?
Thanks for your help.

At 20 yards you should be getting an extensive amount of pellets in the head and neck. Numbers can vary but to get an idea, a good pattern would be 35 or so on up. If you are not getting the results you want, try different ammo first, because it is a little cheaper. If that doesn't work then you can move to trying a different choke tube.

I shoot the 535 and at 40 yards I put 23 in theneck and head with 97 in a 10" circle. I used the Winchester Double X magnums 3" #4 shot.

The ideal pattern for turkey hunting is 100 pellets in a 10-inch circle at 40 yards. This density means that there should be plenty of pellets in the small vital area of the turkey’s head and neck to kill it quickly and ethically.

No. 6 turkey loads (approximately 222 pellets per ounce), then a 2-ounce load of No. 6s should pattern about 25% of its shot in the 10-inch circle. Two ounces of No. 5s (171 pellets per ounce) should give you a pattern of about 30%. Two ounces of No. 4s (135 pellets per ounce) should result in a 37% pattern. These numbers are based on lead pellets, so heavier-than-lead alloy pellets will have fewer pellets per ounce and the percentage will differ slightly.

My gun will put the entire pattern on a paper plate at 20 yards. If I miss the vitals, it ain't the guns fault....

Shoot at a larger target board! You choke should be very tight at that distance, no matter what you are shooting. I would also take some shots at 30 yards, because at that range, you will be able to see any issues with your choke/load combo.

If your shooting a turkey gun with a turkey choke. I wouldn't even waste much time at 20 yards... I would focus more on 30,35, and 40 yards... Even a mossberg should throw a killing pattern at 20 and 30 yards

Well my Mossberg throws a killing pattern at 50 yards. Always make sure you practice at 20 yards as well and out farther. Mossberg is a very reliable gun. Just pattern and practice and then have patience while out hunting...