I'd keep an eye on the used market for original browning mags as the aftermarket mags for these brownings (challenger, medalist etc) don't tend to work all that well.

Yes- I have had problems with aftermarket mags. Bought a couple from gunclips. One works fine the other has problems. The bullets hang up inside the mag. I have been watching for used ones but they are very scarce. And when you find one they want an arm and both legs.
Thanks for the reply.

Check out the Browning section of the Rimfire Central Board. They have some very informative info and users there on the Challenger series.

Thanks- I'll take a look.