Interesting RCBS 44 Special sizing die

[Anonym]

I got a couple odd dies the other day and one of them was an old RCBS 44 Special sizing die. Top of the die reads "RCBS 44.SP.1.K". This is one of the early ones without the threaded hole at the top for the decapping stem. It was in excellent shape, so for giggles I ran a piece of 44 Mag brass in it. That's where I found the "interesting" part of this die.

The only difference between a 44Mag and a 44SPC is 0.125", right? Well, this die has a small step, so that when sizing, the "neck" of the case is sized smaller than the body. The step takes place at 0.80" from the base of the case, so that 0.36" of a Special case or 0.485" of a Magnum case would be reduced in diameter. The inside of the case measures roughly 0.420".

Does anyone know what this is for? The sized body of the case measures right on with my set of Lyman dies, it's just the step for the neck I can't figure out. It sizes back out with a flaring die, but because of the length of this step, the 44 Mag cases are left with an "hourglass" shape to them.

I can try to get pictures if needed.

[Nueces]

Is there a 2 digit date number stamped on the top surface? My RCBS steel straight wall handgun sizers from the 70s and earlier all have this reduced neck area.

The idea was to provide tight neck tension for smaller bullets without oversizing the case body.

[Anonym]

No date stamp on the die anywhere, but this sounds interesting. Are they any better/worse than those without the step?

Another interesting die in that lot was one that looked like an RCBS 44 flaring die, but the die body was aluminum. :confused:

130082

[Bayou52]

I don't know anything about your interesting die, but I could suggest that a RCBS customer rep would be very helpful and could likely provide you helpful information.

Bayou52

[Guesser]

The 1.K is the date stamp. RCBS used that system the first generation of production. You'd need to call to find out what it correlates to.

[Nueces]

I also have aluminum RCBS expander bodies. They are top threaded the same as Lyman M-die bodies. Seems you have a standard, but older, die set.

[Anonym]

Yes, it looks exactly like a standard RCBS die body, but machined out of aluminum with a hardened steel expander plug (marked 44) and has the threaded tip for a decapping pin. I guess I never realized RCBS made aluminum dies.

I was half-tempted to get a decapping rod and turn this aluminum die into a universal decapping die. Seems like it would work for just about every cartridge I reload for.

[EDG]

That is die #1 in the set. I think RCBS dropped that marking.

Depending on your source of information date code K is 1959 or 1960.

[fguffey]

Another interesting die in that lot was one that looked like an RCBS 44 flaring die, but the die body was aluminum

In the beginning, before progressive presses, RCBS made 44 Special dies, the 44 special die set would size and seat 44 Remington ammo. problem! RCBS did not know that so they made a set for the 44 Remington Magnum. Reloaders, in the habit of adjusting dies did not know they were suppose to purchase the additional set. Then came the progressive press, RCBS made neck expanders with the primer punch an integral part.

Another problem, when a press installs primers on station #1 the primer punch must be part of the sizing die. Most ground the bottom of the neck expander die to remove the primer punch. Back to the aluminum die. reloaders that purchases dies before the progressive press received an aluminum die body that was threaded in the top for neck expanding and sizing dies required when sizing and primer punches were moved to the #1 position.


Then RCBS discovered the difference in length between the 44 Special and 44 Remington Mag. It was about this time they added the spacer/shim to the die set, and finally, the sizer die would size both the 44 Special and 44 Remington Mag. The spacer/shim was required when seating bullets 'because' the seating die also crimped. Spacing the seating die up allowed the seating die to crimp the taller 44 Remington Mag case.

And the reloaders that adjusted their dies every time they used them had no clue what the other reloaders were complaining about.

F. Guffey

[Anonym]

Thanks EDG. So the stepped area is a common feature on these older sizers? I just wanted to get my information straight if I decided to move these along. Not really sure I need either one of them. I was after the 38AP Lyman M-die that came along for the ride...

[fguffey]

Your die does not have threads because punching primers and full length sizing had not been invented yet;):smile:

F. Guffey

[Anonym]

Yea, that's kind of what I was figuring fguffey. I was mainly curious as to why they would step down the diameter with the sizer, then flare it back out again to seat the bullet. Seems like a lot of brass working to me.

[IllinoisCoyoteHunter]

Intersting. I have many a sizer dies that aren't threaded for a decaying pin. But, sizing the mouth down a bit more is the enigma lol!

[bedbugbilly]

Interesting stuff!