Pump guns are not picky at all. Shotguns in general are not picky. Every shot gun (that I know of) is ok to shoot led out the box. Unless you go buy a specialized choke you will be fine.
Like was mentioned above. There will be some led particles in the barrel. But that's not a huge deal.
A good friend of mine keeps his 870 in his truck tool box. He has never cleaned it not one time. I know for a fact he has at least 4,000 rounds through it. (We shoot skeet every sunday).Other than some minor surface rust there is not one problem with it. It keeps on ticking.