"Second Strike Ability" is really more of a consequence of design than a design feature for users of modern ammunition and modern technique. I don't know if, and doubt that it was, ever a consideration for the designers of the first DA autos. It may have been if they were concerned about poor quality or hard primers, but I doubt that concern was justified. I could be wrong though, as justified or not the designers may have had concerns. Even then using a second strike is a poor procedure for the rarely encountered defective round. I don't recall when I first heard the term "Second Strike Ability" but suspect it was used in the context of marketing and not design technology.