[DonVoigt]

The area and fit you point out is one of the main problems with the repro drums.
There is a tolerance in the mag well, and the drums are at max or over.

Some drums just WILL not fit some lugers, solution is switch lugers, or reduce the size of the mag body on the drum.

Usually less than half a millimeter is all that is the problem, either use a hammer and tap the "big" spot in, or file it and sand it down a little. then polish and lube.

I have done this to both my repro mags to get an easy fit, and I still have a couple lugers that are so "minimum" that even a modified drum won't slide in easily.