Are there any base pad options around to extend the  CZ75/SP-01/Shadow factory 18 round or Mec-Gar 17 round mags to 170mm?   I scooped up a P-01 that I plan to appendix carry and want to shoot it in the occasional club match just for fun and practice. I'm planning on shooting it in Open to keep the Classifier scores in their own bucket, and I think it would be really funny to run it with a 170mm mag, but I haven't been able to find anything from the usual suspects. Plenty of options fo