I was about to say .45-70 when I read Ivan's post. Sorry Ivan, I think it is a .45-70 bullet, the grooves being grease grooves and the top one the crimping groove. I own, shoot and reload for that caliber and the bullet looks amost identical to the round nose versions I have reloaded. The .45-70 started out as a black powder round being .45 caliber with 70 grains of black powder. It was the standard cartridge for the military until smokeless powder was invented. Think about poor old Custer, as it was his troops primary weapon. The old cartridge has been long lived in that many newer rifles were modified to accept it. And it is deadly for large game when handloaded to about 2100 fps. I have a bolt action model built on a British SMLE rifle, and it is still made for various modern single shot rifles. Monty