Dave Manson Article: Putting The Right Ammo Into The Gun

This is really important with all the ammo choices on the market. Read carefully what Dave told us. "I had a call today from a gentleman who told me he recently had bought a Savage rifle chambered for 'a .300 short magnum cartridge'. When he went to buy ammunition, he purchased new factory Remington ammo headstamped '.300 Rem SA Ultra Mag.' On shooting the rifle at the range, he experienced a large number of failures to fire, and when the cartridges did fire, almost every one split. He sent the rifle back to Savage, along with some of the split cases, and they returned it to him with the invoice marked 'Repaired'. He said that they did not tell him what repairs had been made. On getting the rifle back, he again went to the range with the same ammo, and again had the same problems. At this point, he called us for assistance and suggestions.

"In speaking with him about the rifle, ammunition, and the problems he had, I found that his rifle was chambered in .300 Winchester Short Magnum. The ammo he was buying was .300 Remington Short Action Ultra Mag. Both are '.300 Short Mags'." Both share the same parent cartridge case and have the same head diameter and close to the same shoulder diameter. The .300 Rem SA Ultra Mag was able to fire, I think, because the case managed to be caught by the extractor and the shoulder of the case was close to the body of the chamber, which kept the primer near enough to the firing pin.

"What's all this mean? Be very aware, with the new cartridges on the market, of what the rifle is actually chambered for and what ammo is being purchased and chambered. In this instance, nobody was hurt and no hardware was damaged, but that may not be the case next time ammo names get mixed up. As a gunsmith fitting new barrels, make dead-dog absolutely certain that the chamber reamer and headspace gauges you have match both each other and your customer's request for a particular caliber, and stamp the complete cartridge name onto the barrel where it will be visible when the rifle is assembled. Remember that the two cartridges our customer had problems with are extremely close in appearance, and are easily confused by both inexperienced sales staff and inexperienced shooters."