Anyone out there know much about the Remington 870 wingmaster???

I am new to the shotgun world, my grandfather gave me this goose gun and i have questions about it... It is a 12ga, full choke, pump.

This year I killed my first turkey with it. I would like to know if this gun could be used to shoot, buckshot or slugs as well????

I have been told yes to all and no to all......

What can I do or not do with it.

Thanks,
DM