Q:I came across some old 7mm Express Remington ammo at a gun show. The guy selling the ammo told me I could shoot the Express rounds in my .280 Rem. rifle because the two cartridges are the same thing. He was selling the ammo for a good price, but I passed because I didn’t know if he was telling the truth. Was he right?
A: Occasionally, a manufacturer will introduce a cartridge under one name, and then subsequently change that name (often for marketing reasons). In 1957, Remington introduced the .280 Rem., essentially the .30-06 necked down to take a .284-inch-diameter bullet. For various and sundry reasons, the new round did not sell as well as its originators had hoped, and in 1979 the company (perhaps hoping to capitalize on the success the “7mm” designation had conferred on several other contemporary cartridges) renamed it the 7mm Express Remington.
Although the “new” round was accompanied by some changes in factory loadings, its dimensions were identical to those of the original .280 Rem., and pressure levels increased only slightly (from 50,000 c.u.p. to 50,900 c.u.p) for better performance. Eventually, because of confusion between 7mm Rem. Mag. and 7mm Express Remington, the cartridge reverted to its original .280 Rem. destination. Thus both of these cartridges (as well as the rifles chambered for them) are completely interchangeable.
Other examples of different names for the exact same cartridge include the .244 Rem. and 6mm Rem., .25-20 Win. And .25 WCF, .250 Savage and .250/300 Savage, .32-20 Win. and .32 WCF, and .44-40 Win. and .44 WCF. Many other cartridges have two or more names.