My error, I have the Armory Craft AXG magwell and that works fine as explained, I also have 2 3dprintedgungear steel magwells, I is a full size the same as Sig factory and the other is a 'carry' size which is about half the depth. The full size leaves very little of the mag base exposed but the carry is a little better in that department. Both work fine as they're are meant to.