The curved shape of a bullet (called the ogive) is more consistent than the actual tip on most bullets. Therefore, you can verify the Overall length (OAL) of your handloads more accurately by measuring back from the ogive to the base. Your chamber pressure and accuracy is affected a great deal more by the positioning of the bullet ogive than by the actual bullet tip. Most experienced reloaders keep this in mind when inspecting their bullets; and when measuring the OAL of their handloads, they measure back from the bullet ogive.
. . . . there's more to this story. One day while shooting groups, I started getting totally unexplainable flyers. When I
examined my handloads, I discovered that they varied in length - considerably. This was a mystery at first, because I made all of my handloads on the
same press, using the same seating die, with the same depth setting, and I used the same bullets. So, why did my handloads still measure different lengths
when I measured them from their ogive to the base?
I'm sure that by now, someone out there is wondering "Wait a minute
. . . . if your bullets are seated from contact at the ogive, how can you find a different OAL when measuring those handloads from the ogive to the base?"
The answer surprised me at first, but it's simple. I was taking the final length measurement from a much lower part of the bullet ogive. This
shows that the curved shape of a bullet (the ogive) can vary. This lower part of the bullet ogive is much more significant, because it initially contacts the rifling.
An inconsistent bullet ogive can also affect the distance that your bullet travels to the rifling. This is an important item to look at when you're trying to
shoot tight groups. After that experience, I added another step to my reloading procedure. I now compare my long range match bullets (right out
of the box) from the lowest part of the ogive to the base - before loading them.