Quote Originally Posted by Bigdave35180 View Post
I have had great success using the Dillon c.o.a.l. guages...if they fall in and out of them, they gonna shoot.
The vast majority of the case gauges don't duplicate the chamber of the gun forward of the case mouth. In other words, they don't simulate the throat or leade or rifling. To do that, the case gauge would have had to be made by the same chamber reamer used to ream the chamber of your gun.

You can probably take a bare bullet and drop it completely through the Dillon case gauge. That obviously won't happen with the plunk test in your gun. A plunk test in the case gauge will not guarantee that the round will chamber in any given gun.

Having said all that, I use case gauges all the time to check my loaded rounds. But, it only checks that the brass case will fit the chamber. I will have already verified the COL that I can use for a given bullet, using the plunk test, and I am confident that with the predetermined COL I won't have any problems chambering the rounds.