[ithacaartist]

This is a "Marbles" brand sight, a retrofit from the 50s-60s. I think they are not made currently, but appear on eBay every once in a while. They're easier to see than the originals. You may want to pick up one of Tom's or Ed's for the sake of originality, but if your Luger hits the mark well with this one, just keep using it and reserve the original for later display/resale.

The typical original Luger mag holds 8 rounds. Some, I think, hold 7, but the norm is 8. Ordinarily, it is recommended that you obtain some Mec-Gar brand, new mags for shooting, as they have proven to be the best, most reliable performers in pretty much all variations of the P.08, the Mauser Parabellum, and early Lugers. This saves the risk of breakage of an original mag, and the new ones function well. Yours has a rough spot, dirt/corrosion inside, or needs some lube--There are a few issues that can develop with mags; these are the easiest to address first-off. If no improvement, we'd wonder about spring condition, bent feed lips, worn follower, etc.