RE: do you shoot steel or lead for turkeys
Haven't tried, but I'm guessing mucho damage. Lead will compress and distort when it's forced through the choke, hence it compacts the shot which increases (a) velocity, (b) density, and (c) momentum (or knock-down power).
If the shot can't compress---such as steel---and the choke is made of steel which is less dense than the shot...
Well, I'm a biologist and not a mechanical engineer, but I'm guessing you could mushroom the entire end of the barrel...