Case shoulder push back

[TylerFromMS]

How far is it feasible to push a shoulder back on a case? Say for instance, I wanted to do a long-neck .284? @Fuj have you jacked with anything like this?

 

[WSnyder]

About as far as you want with forming dies. I have a set of John Bunch dies from Butch Lambert but they aren’t available anymore. pbike made some too but I don’t think you can get them either. One of the specialty loading tool companies like 21st Century I think started. Pretty sure it wasn’t them but someone similar.

The Bunch bushings have a radius and work well to rough out a case. I’ve made bushings out of 12L14 with the shoulder angle I want to finish a case closer to dimension.

This is a picture Butch had posted with a set of the Bunch dies and a case he stepped down as an example.

 

[TylerFromMS]

That's pretty awesome. Thanks for sharing.

 

[Fuj]

I was fooling with some of my 284 ELF cats that looked like
nearing case separation. I shortened them even more to get
the 284 case to hold the same load as a PPC but in a much
shorter powder column. I had'nt trimmed them yet but figured
I would go with a 45 degree shoulder just to be different. Like
I say....."Never let a bad Idea go to waste" !!

 

[Sandstorm]

Sorta like a 6-6.5 PRC almost...Yea not exactly.

 

[ArtinNC]

I made a set of neck down button dies like Butch's , I think I got the idea from Butch I use to talk to him often and he give me the blank dies that I used . The center case is a 6mm-284 Lapua and the one on each side is my 6mm-284 short . Made the neck down buttons out of 01 and heat treated them as hard as I could get them , bought a reamer from PT&G for the reloading dies and chambering the barrel . I did all this and I'm still alive today LOL and I'm not a Machinest . .I shot this target with my 6mm-284 short a a 600 yd match . Was a fun project . I'll get a picture of my dies and post them .

 

[AlNyhus]

I would go with a 45 degree shoulder just to be different.

There's strong evidence that after 40 degrees. the case/shoulder junction tends to swell during sizing rather than being pushed back. -Al

 

[butchlambert]

The one on the far right is a 22 Red russian by Red Cornelison. It is a shortened BR case and rebated rim to 222 size.

For fun.

 

[Fuj]

There's strong evidence that after 40 degrees. the case/shoulder junction tends to swell during sizing rather than being pushed back. -Al

You are correct, and my findings also. I've found that once a
case starts to bulge at the case shoulder, It will then implode
into the case. Playing with the hardness of the brass helps.
For general forming I like it annealed. When I get down to
crazy angled shoulders, I like stiff brass with a tight mandrel
and lots of die wax. Let the fire forming finish the job.

 

[JEFFPPC]

Its 93 degrees Fuj, you need to come in out of the sun, lol.