If you're referring to the stock, Bizarro, it doesn't normally come off. I removed it to properly paint the gun. Otherwise, yes, Ghadrack is right. The front of the gun twists off and serves as (horrible) separate blaster.
Are you doing Captain Slug's shotgun-cocking mod, Ghadrack? I'd like to try that myself sometime.
I've only modded my Longshots for range, so far. Add an extra spring, remove the air restrictors, and you suddenly have a very, very unsafe toy. 70 feet, fired flat, with the 'stock' darts. I'm certain custom darts would give me better results, but I suck at making them. 9,9 All of mine tend to pause in midair and perform a drunken Irish jig before falling to Earth.