EOD - I just measured a bunch of them, brass and steel but all the type with the end clips, and they ran from 14.47 m/m to 14.54 m/m. I measured some U.S. 7.62 NATO clips, which are closer to the construction of the clip pictured in this thread, and the ran about 1.34 to .14.36, but one I think is foreign ran 14.54.
Bear in mind, I am not saying that the clip pictured is U.S. made or a Springfield clip. I am only saying that the clips that I remembered using in my Springfield because of their superiority over the well-known version of Springfield clips with end tabs, looked very much like the clip in the picture, especially as to the very black color of them. It may be they were always Mauser clips and I just didn’t know it. They worked great.
Too bad someone there doesn’t have an 03 and some '06 dummy rounds to see how that clip would work.
In checking the Springfield clips, I noticed one has a little round hole in the spring just about center of the clip. Anyone know why? It is obviously not just something someone did, but rather a production feature.