Erfurt Luger Question.

I recently bought an Erfurt on which the mag would not drop free on pushing the mag release. It was binding about a half inch down from the top of the mag. It did not bind until that part of the mag tried to pass through the lower frame near the grip screws. Apparently someone had expanded the width of the mag, maybe in an effort to improve feeding of the last couple of rounds from the mag? Perhaps actually caused by a weak mag spring? Anyway, a little careful squeezing in a vice padded with fiberboard restored the original dimensions and the original function. The mag walls simply need to be narrow enough not to drag on the frame but wide enough not to drag on the cartridges. This was fortunately a quick fix on my mag but could be more difficult to achieve on some other damaged or "owner improved" mags.