Is a Mossberg 500 with a vent rib 28" barrel in 20 gauge enough for turkey up to 40 yards ? Hat are some good 20 gauge turkey loads ? Lead or plated lad only please. Also what is a good xtra full choke for a 20 gauge Mossberg 500 that will shoot plated lead and lead shot #s 4,5, and 6 ?
Yes, that is fine...but change your thinking on shot size. Shoot these with a Sumtoy or IC choke and never look back.. http://www.sportsmansguide.com/net/cb/5-rounds-10-gauge-3-1-2-hvwt-tur.aspx?a=719089
Welcome to OG. Spend some time one night reading through this section and you find what you need.
Unless you are a conscientious objector to the use of any shot other than lead, you might reconsider your commitment to using only lead. If it is a cost concern, you don't have to buy a box of 25 shells when buying Federal Heavyweight shells as they come in boxes of 5 or 10 which will lower your initial cash down. Federal HW 7s and a Sumtoy are bad medicine for turkeys out of a 20 gauge rig. Now dead is dead and lead will continue to kill plenty of turkeys but with the HW-7, out of your 20 gauge, you will have the effective, ethical killing range that one would have with a 12 gauge 3.5" shell shooting a max load lead.
Also for the money spent on different boxes of lead shells to try you can have a choke /shell combo proven to be bad news for gobblers in one step:
Sumtoy 562-5 choke + Fed HW #7 3" 1.5 oz. load = Killer Pattern Combo