Anyone have ideas/experience on this?
I'm going to change a 338 Lapua case to 30 cal and the new shoulder angle will be 40 degrees, giving it a .405" long neck.

Will a bushing type FL sizing die of Jim Carstensen's work fine for this simple change?

How many different sizes of bushings, or how far apart can one go with them and get great results?

Any help's much appreciated.

Not sure what you're doing about the shoulder or how you propose to get 40� out of it, so I can't address that. Because of most dies are hardened I don't believe that guy can alter the shoulder in your die without annealing and re-hardening.

As far as the bushings go, just get the right sized bushing for the neck thickness you want based on the brass thickness. One pass into the right full sizing die will easily bring it down one caliber. Two calibers is also possible in one pass as from 338 to 7mm.

I don't have any experience shortening the body of Lapua brass. However, many times the walls are thicker at the body and shoulder than in the neck. In that case you would need to have a reaming die with the right sized reamer to get correct ID and neck wall thickness all the way down the neck. Using RWS brass for one wildcat, that was the problem in converting 404 Jeffery brass to a shortened case.

Your cartridge sounds like the Flatline line of cartridges, or close to it. That's the 338 Lapua, same neck length, whatever that is, and the shoulder blown out to 40�. I believe Hornady did the dies for it. It may also me similar to the Lazzeroni line. Using one of those might be an easier way to go.

You simply neck down the .338 to .308. And if there are no other changes in the case dimensions, let the rifle fireform the shoulder...

I should have explained a little better.

Not sure if ya'll misunderstood me, I'm not trying to modify a "die", I'm trying to form the "brass" without forming dies, by simply using the FL bushing type sizing die I'm having made to do my normal FL sizing.

The FL die will be a bushing type and uses Redding or Wilson style bushings.

The Redding .335" bushing I have, the 338 Lapua case will not even come close to entering the bushing, it would crumple for sure, as it isn't chamfered much.

It don't even start into the bushing, the .338's "ID." is even larger than the bushing, and the OD. is a hell of alot bigger than that.

How am I supposed to do this in just one step again?

I could have sworn my dad said he had to use "two" bushings to nuck down the 270wsm for his 6.5wsm.

The body length is "not" what is changing the shoulder angle, by blowing it forward, the opposite, the top of the shoulder is being "pushed Back" to make the "neck longer".

This is the goal, longer neck to reduce throat errosion.

The neck is only .305" in length on the standard 338 Lapua, my goal is .405"... hopes that give a better picture of what I'm doing now. I'll need to turn .100" of the shoulder into neck.

The FL bushing die will be custom built by Jim Carstensen with a fired case from my chamber as a referance.

If the shoulder in the die he builds matches the chambers shoulder in length and angle, it will force the shoulder back easily so I can fire form the cases, yes?

Will it simply push both the neck and shoulder "back", allowing it to be fireformed, or will it actually squeeze the shoulder up into the neck instantly giving you the longer neck... or a combination of both?

I'll be neck turning with a K&M and Expandiron die for this chambering, the neck is .335" so they'll get turned to .333".

Thanks for the help all.

use bushing dies no more than .010" smaller than the o.d. of you neck , use as many as it take to get down where you want neck to be. When you get close to the needed inside dia. of you neck that you need, i feel that you will need a standard(no bushing) full length die to do the final sizing. The bushing die i have does NOT size all the way to the shoulder.I am using a Redding full length sizing, bushing die for my 243win. Making the longer neck will also leave you a donut at the shoulder neck junction. If the bullet is not seated deep the donut may not hurt. The donut can be reamed out with the proper size reamer. Just my thought on this, i have never done what you are doing. I have sized 308 win to 243win, close to what you are doing, pushing the shoulder back and getting a longer neck. Make sure you neck is not to thick, you must have room to leave the bullet get out of the case .

Brent,
I reduce 6BR Lapua brass down to 20BR and change the shoulder angle to 35 degrees. The neck/shoulder junction remains in the same place, so a longer neck is created, as well as the changed shoulder angle. It's not as pretty as a fireformed shoulder, but it will work well enough to headspace on the new shoulder. I reduce my cases down in three steps to a hair under 20 caliber, then bring it back up with an ironing die.