XD and HK base pads extend magazine capacity for Springfield XD-series pistols and HK USP/VP9 platforms used in 3-Gun and IDPA's Stock Service Pistol division. Both platforms see steady use in competition despite having a smaller aftermarket than Glock or 2011 builds, and dedicated base pad options matter for shooters who don't want to compromise capacity just because their platform is less common. Arredondo base pads are stocked for the Springfield XD line, built to fit XD and XDm magazine tube dimensions without modification. HK USP and VP9 shooters get compatible extension options sized to HK's magazine body geometry, filling a gap that's often overlooked by base pad makers focused primarily on Glock and 1911-pattern magazines. Stock Service Pistol shooters in IDPA running either platform benefit from the reload-speed advantage of a longer, more consistent gripping surface, while 3-Gun competitors using XD or HK platforms get the same capacity and reload benefits under a stage clock. Fast same-day shipping on most orders at Shooters Connection.