I think a lot of the mod/full chokes was the economy of the times. I think most all 12 ga were used for Ducks, Pheasants and larger birds.A lot of hunters used them with Buckshot for Deer. Rabbits were sometimes likely and Squirrels in tall trees. When I was a kid I was told NEVER shoot a shotgun shell at one Dove or Quail as it was too expensive. My instructions were to catch several Dove on a fence or several Quail on the ground. I would have had a few stern words if I had brought one bird home from one shotshell. I was usually allowed to buy 3-4 shotgun shells ( Peters Victor )at a time-- 60 years ago.