Odd expander die

sherwoods12 · November 11, 2015, 12:49 AM

I bought a used RCBS 45 ACP carbide die set at my local gun shop a couple weeks ago. It was a good deal for $20. As I was cleaning them up I at noticed the expander die was odd. The "head stamp" on the top of the die says RCBS 45 ACP, S. EXP.
I realized the die would in no way work for normal 45 ACP shells.
I contacted RCBS and sent them pictures, they told me it was a special made die for an unknown purpose. They sent me a new expander die, free of charge (gotta love that).
Now I am looking at the "odd" die and wondering what it may have been used for. Attached are some photos.
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Clark · November 11, 2015, 10:05 AM

I made one of those [from 7/8-14 threaded rod on the lathe] in 2011 for some unknown reason.

There are a million reasons for doing anything, but people list the ones that reflect best upon themselves. Give me a minute with my publicist.

F. Guffey · November 11, 2015, 10:48 AM

RCBS marked dies with an X or S. Then there is the rational? or reason for the expander that is too long for a 45 ACP. There are many WCF type chambers that shoot 45 type bullets. Some reloaders/shooters shoot lead. When lead is used the neck must be expanded.

Then there were universal dies meaning the die body was universal. a reloader could purchase one die body with different expanders. Some manufacturers use the same thread in their sizing die and seating die.

And then? RCBS made dies before they had a progressive press. As we all know today the number one position on the tool head is for sizing, punching primers and installing. Problem, the first dies RCBS made had the primer punch in the expander die. I have no ideal how long it took reloaders to figure out what was wrong. I have a few die bodies that are aluminum from RCBS. After all, how tough does a die body have to be to expand the neck of a case?

Any how, there was an abundance of expanders with primer punches around with no purpose until a few friends started chucking them up in lathes and grinding them to fit. The first thing to go was the primer punch.

F. Guffey

mdemetz · November 11, 2015, 11:11 AM

I made one of those [from 7/8-14 threaded rod on the lathe] in 2011 for some unknown reason.

That looks similar to Lee's universal expander for lead bullets in rifle calibers.

sherwoods12 · November 11, 2015, 11:11 AM

I will have to create a drawing with profile measurements. That might help to identify the mysterious expander die. I looks like it can be used to bell the mouth of longer cases, like the .45 long colt or .45-70 gov't. The expander shank is too small for the 45 as it appears to be closer to 9mm.

sherwoods12 · November 11, 2015, 11:28 AM

The "head stamp" on the die is the older RCBS logo. The set this came with has a carbide sizer made by Pacific Durachrome and round nose seater made by RCBS. The sizer works excellent as does the seater.
Thanks to RCBS support, I now have a set that should last me many years.

mapsjanhere · November 11, 2015, 02:48 PM

Attempt to make a 45 Win Mag die?

**44 AMP** · November 12, 2015, 05:31 PM

Here's another thought, in the days before "lowered"ports a lot of .45ACP cases got badly dented case mouths.

The undersize expander might have been made to open back up badly dented case mouths, so that the "normal" expander would work and not crush them.

It appears to have been made from an expander for a longer case.

I have used .357 expanders to "recover" badly dented .45 brass, it seems reasonable to me..

November 11, 2015, 12:49 AM	#1
sherwoods12 Junior Member Join Date: November 11, 2015 Location: IDAHO Posts: 6	Odd expander die I bought a used RCBS 45 ACP carbide die set at my local gun shop a couple weeks ago. It was a good deal for $20. As I was cleaning them up I at noticed the expander die was odd. The "head stamp" on the top of the die says RCBS 45 ACP, S. EXP. I realized the die would in no way work for normal 45 ACP shells. I contacted RCBS and sent them pictures, they told me it was a special made die for an unknown purpose. They sent me a new expander die, free of charge (gotta love that). Now I am looking at the "odd" die and wondering what it may have been used for. Attached are some photos. small.jpg small2.jpg cropped.jpg __________________ "Don't interfere with anything in the Constitution. That must be maintained, for it is the only safeguard of our liberties." -Abraham Lincoln-

November 11, 2015, 10:48 AM	#3
F. Guffey Senior Member Join Date: July 18, 2008 Posts: 7,249	RCBS marked dies with an X or S. Then there is the rational? or reason for the expander that is too long for a 45 ACP. There are many WCF type chambers that shoot 45 type bullets. Some reloaders/shooters shoot lead. When lead is used the neck must be expanded. Then there were universal dies meaning the die body was universal. a reloader could purchase one die body with different expanders. Some manufacturers use the same thread in their sizing die and seating die. And then? RCBS made dies before they had a progressive press. As we all know today the number one position on the tool head is for sizing, punching primers and installing. Problem, the first dies RCBS made had the primer punch in the expander die. I have no ideal how long it took reloaders to figure out what was wrong. I have a few die bodies that are aluminum from RCBS. After all, how tough does a die body have to be to expand the neck of a case? Any how, there was an abundance of expanders with primer punches around with no purpose until a few friends started chucking them up in lathes and grinding them to fit. The first thing to go was the primer punch. F. Guffey Last edited by F. Guffey; November 11, 2015 at 10:51 AM. Reason: move a and add?

November 11, 2015, 11:11 AM	#5
sherwoods12 Junior Member Join Date: November 11, 2015 Location: IDAHO Posts: 6	I will have to create a drawing with profile measurements. That might help to identify the mysterious expander die. I looks like it can be used to bell the mouth of longer cases, like the .45 long colt or .45-70 gov't. The expander shank is too small for the 45 as it appears to be closer to 9mm. __________________ "Don't interfere with anything in the Constitution. That must be maintained, for it is the only safeguard of our liberties." -Abraham Lincoln-

November 11, 2015, 11:28 AM	#6
sherwoods12 Junior Member Join Date: November 11, 2015 Location: IDAHO Posts: 6	The "head stamp" on the die is the older RCBS logo. The set this came with has a carbide sizer made by Pacific Durachrome and round nose seater made by RCBS. The sizer works excellent as does the seater. Thanks to RCBS support, I now have a set that should last me many years. __________________ "Don't interfere with anything in the Constitution. That must be maintained, for it is the only safeguard of our liberties." -Abraham Lincoln-

November 11, 2015, 02:48 PM	#7
mapsjanhere Senior Member Join Date: August 6, 2009 Location: Albuquerque Posts: 2,832	Attempt to make a 45 Win Mag die? __________________ I used to love being able to hit hard at 1000 yards. As I get older I find hitting a mini ram at 200 yards with the 22 oddly more satisfying.

November 11, 2015, 11:11 AM	#4
mdemetz Member Join Date: September 23, 2009 Posts: 73	I made one of those [from 7/8-14 threaded rod on the lathe] in 2011 for some unknown reason. That looks similar to Lee's universal expander for lead bullets in rifle calibers.

November 12, 2015, 05:31 PM	#8
44 AMP Staff Join Date: March 11, 2006 Location: Upper US Posts: 28,833	Here's another thought, in the days before "lowered"ports a lot of .45ACP cases got badly dented case mouths. The undersize expander might have been made to open back up badly dented case mouths, so that the "normal" expander would work and not crush them. It appears to have been made from an expander for a longer case. I have used .357 expanders to "recover" badly dented .45 brass, it seems reasonable to me.. __________________ All else being equal (and it almost never is) bigger bullets tend to work better.