Expander die

[AR guy]

I'm starting to set up my 9mm dies. The Decapping went good, but now I'm setting the expanding die up. I understand that you screw the die till it just touches the shell holder. But the expander inside is where I'm getting a bit confused. How far down should that expander go into the shell, just a 16th into the mouth or does it go further down. And will the depth change with whatever type bullet I use, or will it be the same with whatever type I use? And I know this might be dumb to ask, but the bullet should be trimmed and primed before it is expanded. Correct?

[Alpo]

Well, first the bullet doesn't get trimmed and primed, the case does.

With a 9mm I've never seen the need to trim it. And I've loaded thousands over the years. Straight-wall pistol cases, in my experience, never stretch so don't need trimmed.

I size/deprime, bell, prime, charge, load. Or (if using an older set of dies) size, deprime/bell, prime, charge, load (some of the older stuff, the decapping pin is on the expanding die, and all the sizer does is size),

But in either case, the priming is done AFTER the expanding. If for no other reason than that, every once in a while, you screw up a case. And if you primed it first, you either have to deprime a live primer (which scares some people) or toss a primed case, which wastes that three or four cents.

How deep? Depends on the bullet.

Jacketed bullet, you want the case mouth expanded just enough so the base of the bullet will fit inside. Cast bullet needs more expansion. It's hard to explain. Easy to see, but hard to describe. But, if you try a bullet in the mouth of the first one you expand, and it don't fit, you know you need more. And it's very obvious if you've expanded too much. But unless you have gone waaaay too much, you can still save the case, normally.

[AR guy]

Yea I messed up I know the bullet doesn't get trimmed I did mean the shell. But I did not know that 9mm is good to go with no trimming. Thanks for that info. Ok so it does depend on what kind of bullet. Ok then go lil by lil till i see its good to go. Thank you Alpo.

[Alpo]

I figgered it was just a slip of the keyboard. Just jerkin' your chain.

[gdmoody]

I personally don't change the "bell" on any case, it stays the same whether plated, jacketed, or lead.

[The Joker]

What is this "bell" i keep hearing?

[Alpo]

See how these case mouths are flared out, just a tad? Looks like an upside-down bell, kinda? They are "belled". Crappy picture, but you can see the bell. I, personally, think these are a little "over-belled", but if loading cast, then maybe not.

[AR guy]

Yankin my chain worked, I felt like a fool. Lol.

[stev32k]

The Hornady LNL AP does not have an option to bell before priming unless there is a die that sizes, bells, and deprimes all at once.

[AR guy]

I'm using a rcsb carbide die set and the one die decaps and sizes the other expands the shell and then the last die seats and crimps. Why would it be that way for a single stage and not a progressive?

[gdmoody]

On the Dillon progressive, the stage that drops the powder is also the stage that puts the bell in the brass. I don't know anything about the LnL, but it may possibly be the same.

[stev32k]

On the LNL the first stage sizes and de-primes. The down stroke from sizing sets the primer (stage 1.5). Stage 2 can expand and drop powder or just expand depending on the the set-up.