Yup. That's what it is. I've read accounts (not sure how true they are or if it's just marketing hype... probably the latter, though) that they were used by armories in Spain to load up the mags to send out with their troops, so it's not like they were looking at man-portability.
Other than that, I'm guessing the universal Mag-LULAs are going to be your best option, but they don't use clips. Barring that, as far as I know, it's down to Magazine Loader, Mk. 1... aka: Thumb.