Clearly no one knows what an air bypass is so I will tell you all.
The super soaker 300 (and I think the CPS 3000) have a ball valve on the hose connection that blocks water from reaching the pump, a spring activated check valve hear allows air in at this time. My 300 with water warriors caps on the tank has a draw resistance high enough that it opens with the ball valve open.
It's a feature that lets you replace your pre-charge should you happen to mist shoot, without having to unload. Nice eh?
If you ever bother reading these, I worry for your mental sanity.