Wingmasters are in the 70's vintage. Bolt action 20g is not screw in. Slug gun is not gonna work. Outside of that, I am NOT taking my o/u out in the field to throw into the mud and weeds while coyote hunting. I will have to double check the older Winchester I have. It might have screw in chokes but I am thinking not. Can't even remember the model on it but it is the longest barrel i think. Not such a quick and easy shotgun to swing around for close range shooting when you are sitting on the ground. I will check them all though. thanks for the offer 57!