Vintage Lyman Sizing Die Identification

[edmedm]

Recently acquired a vintage Lyman All American 2 Die Set.

The original packaging indicated 7 M/M REM MAG, but the "REM MAG" has been crossed out, and based on a few quick measurements I agree that the die is not appropriate for 7mm Rem Mag brass, but I am stumped as to what commercial cartridge the die set will fit.

Marking on die state "Lyman 7 MM FL", shown in photo.

Note that measurements were taken quickly with a set of digital calipers, not perfect, but hopefully close enough to facilitate product ID.

OAL of die body is 2.818".
Sizer ball diameter is marked 283, and measures .283".
ID at die base measures ~.467".

Cartridge base to shoulder is 1.748".
Cartridge base to neck transition is 1.945".
(For these length dims added typical .125" shell holder height to measurements taken from die.)

I have compared these measurements to various 7mm cartridges and have come up dry so far.

Any help identifying the intended use of this sizing die will be appreciated.

 

[LoneTraveler]

By the die diameter you have posted it is close to the 7 X 57 Mauser case. On the case drawing in the Hornady 7th edition as .471 body at the edge of the extractor grove. With your measurement of .468 that would give 3 thousands under size not counting the brass return memory. If those dies go back into the 1950's There was only 7mm (7X57) the 7 X 61 Sharp and Hart and 7mm Weatherby as commercial cartridges in the USA. The 7mm and 8 mm in my 1963 Hornady book printed in 1967 just list them as 7 mm followed by (7 X 57) and the 8 mm followed (8 X57). A call to Lyman may be a quick way to verify the markings. Good Luck ion your quest.

 

[edmedm]

I have a Lyman #45 reloading manual that was printed in 1970, seven years after the referenced Hornady manual, but the Lyman manual identifies the cartridge as "7mm Mauser (7x57)", not just "7mm".

Allowing for measurement error the die dimensions agree closely with 7mm Mauser specs, and the Hornady manual provides evidence that "7mm" was at one time used synonymously with "7mm Mauser" and "7x57".

I do not know when Lyman converted from the old black cardboard boxes to the plastic orange style, or if they ever did change die markings to read 7mm Mauser or 7x57. However, the packaging likely indicates that this is an older set which could have been produced during the time before proliferation of other 7mm designs, when shorthand "7mm" was description enough.

One wildcard is the modified "7mm REM MAG" labeling on the box (was it the original box with label corrected at Lyman, etc.) but no need to head down that path. The die "is what it is" and therefore the topic of interest, not the box which could be misleading.

I agree that the die in question is very likely a 7mm Mauser/7x57. To confirm, I'm in the process of chasing down a couple pieces of 7mm Mauser brass to run through the die. If that experiment fails I can give Lyman a call, but I doubt that I will have a need to do so.

Thanks for the excellent, detailed response with solid historical references.

 

[LoneTraveler]

I have a Lyman box that is black with the slip on lid. I bought it in 1972. It contained a 3 piece set of 357 Mag. with a carbide insert sizing die. I know it was 72 because it was in months of Aug. 71 when I went to work as a wildlife officer and carried a 357 mag. as a side arm. This would be in 7 mm RM time for the label on the box. I would measure the 7 X 57 case and write the measurements down. Then compare after running through the die should tell the story. Best of luck on this quest.

 

[edmedm]

I finally received sample pieces of 7mm Mauser (7x57) brass and successfully ran a piece through the die. The piece on the left went through the sizer, the one on the right as-fired. Pre/post sizing measurements showed small dimensional changes, as would be expected for the proper die.

Another interesting piece of information was available on one of the pieces of brass. As can be seen, the piece with R-P headstamp is identified "7 mm (7x57)", further evidence that the 7mm Mauser/7x57 was simply called "7mm" at one time.

Thanks for the kind assistance in the positive identification of the die set.

 

[MudRunner2005]

You could always have a chamber-cast made of the die, and then have it measured to find out exactly what cartridge it is for. That's the only true way to find out specs, if everything else is unknown.