I was thinking of cutting some plastic pieces out of the same kind of material that fish filleting boards are made of...you know, the polyurethane kinda plastic...I don't know what else to call it.
Anyway, if I cut it the same size as the bottom of the mags and then actually trimmed it a bit to fit inside the bottom of the magazine base, it would be perfect. I'd even glue them in if I could. I can't see ever needing to remove them once they are in. Ideally, it would be nice to have a CNC milling machine to mill some aluminum stock that would fit perfectly inside the base.
Anyone have any other ideas?