[QUOTE
The .30-30 Winchester/.30 Winchester Center Fire/7.62×51mmR cartridge was first marketed in early 1895 for the Winchester Model 1894 lever-action rifle. The .30-30 (thirty-thirty), as it is most commonly known, was the USA's first small-bore, sporting rifle cartridge designed for smokeless powder. In Mexico and Latin America, it is known as the treinta-treinta (Spanish for "30-30").
.30 WINCHESTER SMOKELESS first appeared in Winchester's catalog No. 55, dated August, 1895. As chambered in the Winchester Model 1894 carbine and rifle, it was also known as .30 Winchester Centerfire or .30 WCF. When the cartridge was chambered in the Marlin Model 1893 rifle, rival gunmaker Marlin used the designation .30-30 or .30-30 Smokeless.[9] The added -30 stands for the standard load of 30 grains (1.9 g) of early smokeless powder, according to late-19th century American naming conventions for black powder-filled cartridges. Both Marlin and Union Metallic Cartridge Co. also dropped the Winchester appellation as they did not want to put the name of rival Winchester on their products.
The modern designation of .30-30 Winchester was arrived at by using Marlin's variation of the name with the Winchester name appended as originator of the cartridge, though .30 WCF is still seen occasionally. This designation also probably serves to avoid consumer confusion with the different yet similarly-shaped .30-40 Krag, which has been referred to as ".30 US" and ".30 Army". ][/QUOTE]
