Written by Ballistic Technician Philip Mahin
The cartridge you shoot has a specific nomenclature designated to it, but does it mean what you think it does? If we step way back, two cartridges come to mind easily, a 45-70 Government and the 30-40 Krag-Jorgenson. In one version, the 45-70 military designation was .45-70-500 and that indicated they were using 70 grains of blackpowder behind a 45 caliber bullet that weighed 500 grains. Does that mean the 30-40 Krag used 40 grains of powder behind a 30 caliber bullet? Yes, but it used smokeless powder instead. So this type of naming system stuck for quite a few years, for instance, a 30-30 Winchester (again 30 cal. and 30 gr. of smokeless) is a good example of a cartridge that has stood the test of time.
This brings us to a new military cartridge, the 30-03 for the Springfield rifle. Does this mean there was only 3 grains of powder in it? No, the 03 represents the year it was adopted to service, albeit a very short service. Three years later, the cartridge was changed to the 30-06 that we all know today and that’s why you will sometimes see it listed as 30-‘06 Government or 30-06 Springfield or U.S Cartridge, Cal. .30, Model of 1906. Incidentally, the 30-03 was not a total waste. Even if only by inspiration, by necking it down to hold a .277” diameter bullet, it resembles the 270 Winchester doesn’t it? This brings me to another point, the reason the 270 Winchester is called a 270, but uses a .277” bullet. I’ll discuss this next time, but until then, be safe and have fun shooting.