RCBS Die Identification please

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  • Last Post 26 March 2024
SkinnerD posted this 26 March 2024

Hi there, hoping some knowledgeable person can identify this die for me. Its internals looks like a simple straight tube which leads me to suspect it is a bullet sizing die for use in a Lubrisizer. I have never used one of those or seen one in the flesh. I guess it requires a top punch to be complete or useful. Planning to move it on so need to be able to describe accurately. thanks in advance. J.

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Side view

John - New Zealand

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Aaron posted this 26 March 2024

In the top photo, is that hole threaded? Looks like either a sizing die or case mouth flaring die, either of which are missing the decapping plug or the flaring plug. If the top hole is not threaded, it has been customized.

In photo two, there seems to be a carbide sleeve in the hole, If so, it's a sizing die.

 

With rifle in hand, I confidently go forth into the darkness.

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SkinnerD posted this 26 March 2024

You Sir are very observant. On close inspection - yes, there is a sleeve in the bottom. And, using a toothpick to scrape down the inside of the top of the die the wall is smooth except for a very shallow ring, a gnats hair wide, about half an inch down..it can be seen if I shine a light down. It may be my now educated imagination but at the ring the internal hole dimension appears to decrease.. So perhaps you are correct and the plug thread has been removed. Not hard to do I guess, but why? To make it into a push thru bullet sizing die? Removing the plug from a carbide Pistol case sizing die simply removes the decapping function, yes? There is no internal sizing button for a straight wall case. What other applications may the modifier have had in mind I wonder?

Mic'ing the inside of the die at the base I get .372in

I can drop a lubed 358 sized cast bullet through with a little push from a rod. 

So someone had a well-worn or over spec 38sp/357mag barrel ?

Or needed a powder-thru die?

Edit:

The plot thickens. I ran some brass through, 357Mag. It is very tight and the last part of the stroke takes some push. The sized brass is well scored per photo. ALSO the die puts a very shallow bottle neck in the brass - .377 down to .374

You can clearly see this in the photo. The two outside cases have been run through, the middle not, I cleaned the die inside with a twist of fine steel wool run on a plastic rod in my drill. The scoring of the brass remains. 

2 Sized Cases, middle unsized

John - New Zealand

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RicinYakima posted this 26 March 2024

John,

This is an early RCBS sizing die from the 1950's. It has a letter code date and no year of production. Early sets had this sizing die, the second die had the depriming rod and expanded the case mouth. Third die was seat and crimp.

The main issue was that the second die would only fit one length of case. That is why the die is marked "357 MG" as it was not adjustable for 38 special cases. 

By the early 1960's, all US made dies deprimed with the sizing die. 

HTH's, Ric

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Aaron posted this 26 March 2024

Well there it is!

 

With rifle in hand, I confidently go forth into the darkness.

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MP1886 posted this 26 March 2024

John,

 

By the early 1960's, all US made dies deprimed with the sizing die. 

HTH's, Ric

 

That's not exactly correct.  I have quite a few sets of dies newer then the 1960 timeline that don't have the depriming setup in the sizer die. Bottleneck rifle/pistol dies yes, but straight walled no.  

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MP1886 posted this 26 March 2024

The OP said he measured the inside of the die at the base at .372. Next he said when he sized some in the die they measured .377 and that at the mouth they stepped down slightly to .374.  It's pretty hard to get an inside diameter measure unless you have a very accurate tool to measure.  Some straight walled revolver cartridge dies did have a slight step down at the mouth end where the bullet would be seated. Some were very pronounced.  This cannot be a flaring tool for many reasons. One is a flairing tool die body is has a much larger hole in it so that the flare can be produced. I don't believe it's a carbide die. Easy to check if it is carbide as it would by much harder then the rest of the die metal. The die apparently at one time, or more, got grit in it and scored the walls of the die. Carbide dies don't normally do that and carbide dies are also normally smaller diameter where the carbide ring is then the rest of the hole through the die. It's very important that your brass is clean and well lubed or scoring the die can happen.  This is nothing but an older steel 357 Mag die manufactured in 1953. RCBS may replace free if you call them. (800) 533-5000 

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RicinYakima posted this 26 March 2024

MP1886

You are correct, C&H made dies for some of their presses to the last run of the Straight Lines. Also ECHO and I believe MIcro-Precision made some into the 1970's.

Ric

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SkinnerD posted this 26 March 2024

You guys are awesome!

Yes my calipers are relatively cheap Hornady Dial Calipers for Reloaders. Probably not the finest tool ever made but equally probably better than the nut holding the wheel lol

Not sure I have a use/need for it but seeing as 1953 was the year I was born it might go on the memento shelf.

I guess if I did use it I would recognize my brass on the range easily.

Anyone ever use one of these to size an over-dia bullet? An idle thought, an idea lacking an application but there ya go.

Thanks all.

John - New Zealand

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MP1886 posted this 26 March 2024

 Not sure I have a use/need for it but seeing as 1953 was the year I was born it might go on the memento shelf. 
I apologise Skinner, I meant to hit the 1956 key.  As for using it for a push through sizer die most of those have a short sizing section at the mouth of the die rather then the whole dies sizing the bullet down.  That also makes it easier to push the bullet through. I'd still give RCBS a call. Most the time they want to replace stuff for free and will actually argue with you that they want too LOL.  I told them one time that I'd pay for it. 

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SkinnerD posted this 26 March 2024

All good. I spent a couple of moments with a bit of guncloth in the end of a slotted plastic rod (piece of micro-watering system tube) and a liberal slop of Flitz paste. Turning high speed in my battery drill in and out a few times and the scoring on the brass is all gone.

RCBS have been very good to me in the past shipping warranty items all the way to NZ at zero cost. It would seem a little frivolous to me to ask them to replace a 67 yr old die that has likely more than earned its keep and is still, now, perfectly serviceable. If I was a $5 UPS parcel away from them I'd do it. But min shipping Down Under is of the order of $50USD these days. I think I'll save it for something a tad more important to me. In the meantime a little mystery has been solved and no doubt I'll find a home for it with someone who just wants to perfectly size 357mag brass.

Thanks again to all..excitement over, on with the day

:-)

John - New Zealand

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Aaron posted this 26 March 2024

RCBS, Lee, and Dillon have all sent me replacement parts that I have worn out. Dillon REFUSED to allow me to purchase a part I BROKE. All they would say on the phone was "Lifetime no BS warranty." Heck, I broke the darn thing. This is the customer service that brings us all back. The investment they make in their customers comes back to them in spades.

 

 

With rifle in hand, I confidently go forth into the darkness.

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