The 11-87 was a revised version of the 1100, it was designed to be less ammo fussy, whereas it is not as nicely finished as the 1100 it is a decent semi-auto and would certainly be a decent upland gun. The principle operating difference is in the gas system, the 11-87 is pressure compensated, the 1100 is not. The 1100 lives on an the premium target model these days wit the 11-87 filling in as the field model that can handle a variety of loads.