Rock Island Armory offers purpose-built 140mm and 170mm basepads for USPSA shooting. This base pad adds a little extra internal volume -- and squares up the design for positive reloading.
The same design works great on the standard-length mags as well (when used on a Rock Island pistol with the factory magwell).
Better yet, your magazines will still fit the USPSA gauge with out a problem.
Currently available in black, red, shiny aluminum and brass.
Find them on our website at https://taylorfreelancestore.com/rock-island/