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.
Does not really fit VFC Glocks unless you are brave enough to do a bit of filing where the stock touches the base of the gun. You can mitigate the wobbling by putting some tape around to make it a tighter fit. I can't speak for other models and how it fits but it does the job for now.