Now that this thread has run its course, and I apologize if it has not, I wish to add a historic aside relative to Zinc and Cast Bullets. Most here will not likely be old enough to remember the Lyman molds that had a bullet design shape somewhat like a collar button and the mold had a relief cut into the cavity for the purpose of holding a zinc washer, resulting in a bullet with a zinc washer infused around the circumference of the the bullet. As I remember it (being old, I can be wrong), the purpose of the zinc washer was to create and maintain distance between the lead of the bullet and the rifling so that the bullet would not lead the barrel. As I remember, even at that time, it had been dropped from the Lyman catalog and was likely from as early as the twenties to as late as the forties. Seems like it was only available for the .45 ACP.
Does anyone else remember that abomination?