Hello gentlemen, I decided to weigh in here and offer my opinion... keep in mind, that it is only an opinion, but it is based on closely inspecting many, many, alum. WW2 Mauser mag. bottoms ... and here is what i've come up with... The polished area that Ron (wish I could take pic's like that Ron!)has outlined, is most likely done to prep the bottom for numbering, and it was primarily done to remove flashing. If you dissect one of these bottoms you will find evidence of both porosity and parting lines under the surface... They were made in at least a two or three part mold, probably injected.. The polished area was done on a belt or against a wheel that was soft & most likely turned quite slow... probably, the bottom was held by hand in a fixture of some type, to hold against the abrasive.. That is why they have that butterfly wing appearance on the polished area.. The polish lines are fairly consistent from mag. bottom to mag. bottom, with just enough variation to point to hand done. Most of the time they will exhibit more prep on one side or the other.. But by and large, most are done well... I would not hesitate in buying that mag. as an excellent original specimen... I would love to talk to the guy that stood there all day and did that operation... bet he was a busy guy! best to all, til...lat'r...GT
