RE: What is run out???
 

Hg thanks for taking the time to explain that...

I'm going to give it a try:)

RE: What is run out???
 

Runout comes in two main varieties, bullet and case. In both "cases," the definition has to do with how far off the object being measured (case or bullet) is from its own center axis, which should -- of course -- be in line with the center axis of the bore. It just stands to reason that if things are lined up with the bore (especially the bullet), you'll have better accuracy.

Bullet Run-Out Depiction.
The below drawings are exaggerated for viewing and demonstration purposes of bullet run-out.
(a) .000" - .002"(b) .003" - .004"(c) .005" - .010"
In the above drawings depicting bullet run-out, if you have worked up a good load,
(a) will give groups under 1/2 inch in most cases,
(b) will give groups under 1 inch in most cases and
(c) will give groups between 1 1/2 inches - 2 1/2 inches.
Determining or Diagnostic For Bullet Run-Out.
The above conditions will go unnoticed by most reloaders because you have to check bullet run-out with a accurate run-out gauge. If you go to the range and are consistently frustrated with group size and bullet flyers out of a good group and you have followed the steps in my accuracy guide read on.