Yesterday I recovered two Winchester white box (WWB) 50-round 9mm Luger boxes lot number 30DA21 (12 January 2010) and 91 associated cases all with the same firing pin impression; 23 headstamped (+) (over) WCC 10 with crimped-in primers, 45 headstamped WIN (over) 9mm LUGER, and 23 headstamped WIN (over) 9mm LUGER with crimped-in primers exactly like the WCC’s. Now I understand why I recover so many recent WCC headstamped NATO 9mm cases – they can come in the WWB boxes. But crimped in primers on standard WIN 9mm cases is a new one on me and I’ve gone through tens of thousands of WIN 9mm cases without seeing any before. Anybody else seen the standard WIN 9mm cases with crimped in primers?
The only theory I could put forward is that the cases were made for some Govenment contract originally which specified crimped primers and then not used and recycled back onto a civilian production line. Crimped primers represent an additional process in manufacturing so its unlikely to happen without a reason.
Most 9mm pistols have locked actions so a crimped primer is superfluous, its only when you get to using them in a SMG with a blowback action that you might consider it necessary.