Actually, Mr. Dave Corbin has several of his books posted on his web site for review /free dowload, etc. (corbins.com, swage.com, etc.) and addresses this in one chapter at least. Both "brass" and "bronze" are ancient metals. Brass is copper and zinc if I recall and bronze is copper and tin. Point is that "commercialism" has entered the picture long ago and stayed. There are "brasses" that are not brass but just called brass. And bronze products that are not bronze but called bronze for commercial purposes... Then there are the ratios in the "mix." Mr. Barnes built his business with bullets made with copper water pipe, relatively pure copper. Hornady, Sisk, Speer, Huntington all got their starts making .224 bullets from fired rimfire cases. You may have noticed that there are many appearances to rimfire cases and if you get into some real antiques, they are pure copper, relatively--"tech pure" 99% or so... So there are many possibilities. Is there a diferent polish in use? Or was some other alloy required or just cheaper??? Happy holidays. luck.
