I was just over on the Smith and Wesson forum,
www.Smith-Wessonforum.com, and found a discussion regarding the primers to be used with certain brands of S&W500 brass. It seems that some manufacturers are switching from large pistol primers to large rifle primers. The headstamp on the brass is being modified to show the rifle primer. Since some of you are currently loading the S&W 500, I thought this info might be of impotance to you. Go to the "Reloading" forum and go under S&W 500. About the third or fourth post down you will start to see lots of discussion regarding the primers.
From the Starline website: [*Changed to large rifle primer pocket effective 7/28/03. See information on Product Description page.]
Hornady brass still uses a Large Pistol primer in their cases.