Kletust -
Welcome aboard !!The answer is that it's a function of BOTH the brass
and bullet.
They are both unique individuals. So you really have to take your brass and your bullets and answer your own question. No need to listen to anyone else who doesn't have the exact same bullet and case, because it just doesn't matter.
We like to see at lease 0.200" of bullet insertion for 9mm Luger, but,
from the bullet's point of view, there is no limit on what's too much. Concerning the base of the bullet, the case is the determining factor because the case gets thicker as it it deeper. The bullet, when inserted too far, will simply bulge the brass on the exterior so that it no longer fits into the chamber. You can't see it, so you have to check for this by using your naked barrel as a measuring tool.
Concerning the nose of the bullet, the interface between bullet and chamber is the limiting factor. That's what the "push test" is all about. Max OAL and the bullet length will give you the necessary case insertion depth.
147 Gr. Blue Bullet - All bullets will plunk test at 1.125 OAL (meaning they give that nice plunk sound and will fall right out if you turn the barrel over), but will not consistently freely spin until I reach about 1.115". I loaded about 500 at 1.125 and had one miss feed out of the batch and they shot very accurately. At this length I have about .310" of bullet seated into the case and you can see just a very slight hourglass shape in a loaded round. At this length, I get maybe 2 or 3 out of 100 that don't pass case gauge. If I shorten down to 1.115 then I start to notice more hourglass shape and I start to get 4 or 5 out of 10 that don't pass case gauge.
1) Forget the case gauge.
Use your barrel.2) The "plunk test" will give you "yes or no" answers, but it will not tell you what OAL you should be using to cover 100% of your rounds. That's because the plunk test doesn't take into account the variations in finished OALs that are bound to occur. And that's why you get 2 or 3 per hundred that don't pass.
At this stage you need NUMBERS to work with. So you must use the hard data that comes from the "push test". It's the difference between going to a job interview and the company says, "Oh, don't worry. We'll pay you a lot." Versus "You'll be paid $xxxx per month."
In some things it's just nice to be
exact.
