Smoke the shoulder, neck and bullet. Chamber the round. Then open the bolt and remove the shell. Check the cartridge where you smoked it. You will see marks where you are touching either the chamber or the throat(lands of rifle). Simple process. If you do not see any marks then smoke the bottom inch of the shell. If you do not see any markings then take your rifle to a competent gunsmith.

Did you measur the overall length of the cartridge?? Or did you measure it to the Ogive?? Tom.