if you can't can't shoot steel out of the std full choke then you can't shoot heavi shot out of it either. i have the same win pump except it was a ted williams branded for sears. i believe they say to not shoot steel out of anything tighter than mod on those chokes. if you are shooting lead then go for it.
I've shot lead Remington nitro turkey out of it before but good point. That is something I should be double checking.
How about the 1187? I've never shot anything heavier than phesant loads out of that
