It was formally known as cartridge, 30 06, as it had a .30 caliber bullet and it was officially issued in 1906. It started out in life as a 30 03, which was a slightly longer case, but it was scaled back a bit before being issued in its final form. It was used extensively in service arms from world war I on through Korea. It had a sporting life as well, and is the most commonly available high power round in the US. You can get bulk ammo for a reasonable cost through Cabelas if you can save some sheckels!