.500 S&W Magnum
Date: Apr 23 2020
The .500 S&W Magnum was a joint effort between COR-BON Ammunition and Smith & Wesson, which propelled either a 400-grain JSP or a 440-grain cast bullet over 1,600 fps. This power level required S&W to develop its new X-Frame revolver. At 74 ounces (8 3/8-inch barrel), the revolver was large and weighed almost as much as many ultra lightweight hunting rifles. Nonetheless, sales were brisk for several years.
Within the first few years there were technical changes to the cartridge, mostly minor; however, early COR-BON and Hornady ammunition featured Large Pistol Magnum primers, with primer pockets sized accordingly. Some ballistic labs began to experience erratic pressure curves, and select maximum loads were occasionally piercing primers. As a result, primer pockets were changed (deepened) to accept large rifle primers. For several years factory loads were available that contained both primers, but eventually all have changed to the Large Rifle primer and cases have been changed accordingly. Incidentally, all Starline cases that are manufactured with the Large Rifle primer pocket will have the standard “.500 S&W MAG” headstamp and “R”.
It is not advised to use Large Rifle primers in cases that feature the Large Pistol primer pockets, as they will not seat below flush, but rather protrude and often drag on the recoil shield, potentially stopping cylinder rotation. A high primer in a heavy recoiling revolver also has the potential to be dangerous.