7 mm was originally a German mauser caliber used during WW1 and WW,developed during the later part of 1800's,(1880-1895).30-06 was developed by Springfield arms in 1906 for the military.It was used extensively in WW1 and WW2. The US military got involved in creating a new shorter round for the military and ultimately decided on the 308(7.62mm), now a nato round. This was used in the latter part of WW2 and Korea. When we got involved in the Vietnam war, a new smaller caliber was developed for close range jungle fighting, the 223(5.56mm). Almost all these popular calibers have been used by sportsmen over the years for easily accessible ammunition and reliable weapons for hunting. 7 mm magnum sprung up as a new caliber for hunting, offering more power and range than either the 30-06 or 308.It was actually a German caliber used during the WW2, but after the war Mausers were bought using this caliber and proved to be reliable and accurate.A large following soon caused the ammo and gun producers to build a better,more powerful version of these,the 7mm magnum.Then the 30-06 was necked down to create the 270,which has more long range capabilities than the 30-06.FYI rockhound