The only thing that I ever heard about this was one day I was loading shotgun shells and a friend dropped by, when he saw what I was doing, he asked if he could could have a few for one of his friends who drops one in his mold when casting spire point .30 calibers for a 30/06, he didn't know why it was done, but I'm thinking possibly the hardness of the lead shot would help in keeping the tip from deforming, but this was lead shot, not steel BB's..............steg