Magwells are designed to allow for faster reloading of the semi-auto by giving you a bigger opening that is flared and beveled to guide the magazine home. Is almost like, if you get close enough the magazine will just find its way in on its own. Most can be easily removed, depending on how they were installed.
Was leaking out of the box, needed a little teflon tape on the pierce valve thread and a new silicon O-ring on the output valve and now it works perfectly. Not a lot of shots per filling though.