Hi Tom, In theory, all mags should interchange with all Lugers! But, time, use and abuse has rendered a large portion of original mags, especially folded sheetmetal type, over the maximum tollerance for fit and function. At the same time, some, not all, of the Lugers may have been accepted at the minimum tollerance for the dimensions of the mag well? It becomes even more critical when trying to resize drum magazines to fit the majority of Lugers. For personal testing, you're going to need a few lugers, and a few magazines, because you'll find that the larger the test sample, the easier it is to define a problem? Over a testing period, you might be able to determine which lugers have tight tolerances, and which are quite loose. I used my magazine straightening tool/ mandrel, (it is precision ground to within .0005" top to bottom) with shims to determine what my existing Lugers had for dimensions, and then could use the same method, mandrel and shims, to measure, test, and determine trouble spots in problematic Lugers. It's weird, but you can hardly see or feel it, but once you find it and correct, it's like a 100% improvement.. So, you need accurate tools, to measure, and to modify and repair. I think this was a real issue on the assembly / manufacturing lines, as most all lugers show sings of broaching and filing in the mag wells? I can do the repair easily because I've aquired a feel for what has to happen, and where it needs to happen.. It's not hard, but you'll need to do a few before you are comfortable with the process... On the other hand, I have a byf frame on my test gun that has a square but minimal chamber dimension, and when I repair mags or drums, they need to fit that gun, or they're not correct and need more attention... You have to approch the repair carefully, as the objest is not to enlarge the whole mag well dimension, it is only to correct the abnormality that is impinging on the mag? Let me know what you'd like done, and I can certainly take care of it... best to you, best to all, til.....lat'r....GT...
