If your shooting lead I would try the smallest shot you can find #6 ? with the" factory full " and make sure it shoots POA before venturing out in the turkey woods - you stand a good chance of making it a 40 yard gun as is.... 10 gauges can do this
Im not sure what the constriction and construction of your factory full is but if its just plain full , and if it is determined you can shoot a Federal Flight control wad , I would steer you towards the Federal 1300 fps #7 Heavy Weight offering , the wad may give you a fighting chance of putting more than 100 in a 10 at 40 yards - Im saying this because with just the full choke your options are limited - the choke will make a big difference because I have seen turkey chokes throw that shell from 130 all the way up to 218 - the choke is a big deal with that shell
A box of those (5 count) will set you back about $29
Good luck , let us know how you did --Shannon