T. O'Heir,
Ah! I didn't catch that the COL came from Hodgdon. OK. That makes sense because it is a different brand of bullet, so, of course, the length isn't identical and the cannelure is not in the same place. Apples and oranges.
mikld,
If he uses the Hornady suggested length, the cannelure will be in the right location anyway.
ReloadKY,
All that Hodgdon info is for the test bullet listed. When you change that or any other component, you go back to the bottom load and work back up, watching for
pressure signs, but use the manufacturer-suggested COL until you get comfortable enough with reloading to experiment more. One reason for using the manufacturer's length is will ensure the particular ogive radius they used (the nose side shape) doesn't jam into the lands of a standard SAAMI chamber, thereby raising pressure.