Originally Posted by SidecarFlip
If you extend the decapper pin in the Neck Sizer die by running it down until it sticks out excessively, you'll pop the primer long before you intrude in the upper cavity of the die and begin the neck size operation.
When you use the neck sizer as a decap die you never advance the ram all the way to the top. You'll feel and hear the spent primer come out. Thats all the farther you go.
I don't use a neck sizer on a 338 case, never have. if you set the FL sizer die correctly, you won't overwork the brass in the first place which is what the neck die is attempting to avoid but thats mot germane at this point.
What is, is getting the expander ball down in the die with the decap pin removed. You must remove the pin and it's collet or the collet will bottom on the flash hole and deform it at the top of the ram stroke. Not a lot to play with space wise but it's doable.
What will occur is, the expander ball will size the ID of the neck and continue into the body of the case (as the ram is advanced upward and the case rises into the die body). The neck then rises up into the upper (neck cavity) and the reduced diameter sizes the outside diameter but without the expander ball attempting to hold the inner diameter which causes the brass to flow and the case to grow. I want you to set the die off the shell holder because I suspect you have already bumped the shoulders back too much as it is. Thats neither here nor there at this point. Lets just get the neck tension sorted out.
I also think you'll find the case sizes a whole lot easier. You aren't fighting the expander ball against the neck cavity with the case neck wall between the two. Of course assuming that the case mouths aren't work hardened. I'm not there to tell so thats a crap-shoot.
You still need to get a Cartridge Overall Length gage from Hornady or Pacific Gage to check the shoulder datum as it relates to your chamber. Bottleneck cases locate on the shoulder of the case so the datum measurement is critical to concentricity as well as smooth ejection, just like neck intrusion into the throat area.
Thats for later on. Right now, order the case gage and get the neck tension under control. You might want to look at a VLD reamer for the case mouths as well. They are cheap (RCBS has one for 12 bucks). They make bullet insertion, especially boat tails, much easier and the bullet don't get scratched by the case mouth as when you use a normal case mouth reamer.
After reading through this thread I have to agree with what Flip has told you. You should not be able to push the bullet into the case simply by closing your bolt. This means you have too little neck tension to adequately hold the bullet in the case mouth.
You should be able to rectify this doing what Flip has told you to do.
I'm imagining that you have been overworking your brass if you have only fired your cases twice, and have had to trim quite a bit of excess brass off of your cases. After 2 firings I usually have very little brass to trim off. I do it just to make sure that all of my cases are consistent.
I agree too that it would be easier to help if we could see what you have going on. If you know anyone in your area that is a competent loader I would have them come over and help you out.