question regarding remington 870 magnum

Just in case I am not confused... A Remington 870 Wingmaster is a pump shotgun, not a semi-automatic. You have to pump it to load the next shell after firing. Shoot, pump, shoot again. :) It should shoot both 2 3/4 as well as 3" shells.

If that wasn't the issue, I apologize for the Madden-esque description. :)