What do I have here? A Lyman 310 tool in 8.6 mm.

[slug]

A recent find. A steel handled set marked 8.6 x 56. The box and two of the dies are marked 8.6 x 56 as well. There is no reference to any 8.6 cartridge in Cartridges of the World, or on the internet.

[sigep1764]

That is a NICE looking set of handles...

[ascast]

what do the dies say? maybe for 8mm Hungarian or some other.

[skeettx]

https://en.wikipedia.org/wiki/8%C3%9756mmR

[slug]

The 8 mm. cartridge isn't 8.6 mm, and the cartridge is rimmed. The priming chamber in this set is for a rimless cartridge, the same size as the .30/'06.

[Rich/WIS]

8.6mm is about .338. A chamber cast of the die might give better idea of what it looked like. Don't you just love a mystery.

[skeettx]

VERY close to a 338x57 wildcat cartridge, hmmmm?

What is the number at the top of the M Die, expander die ?

[Reverend Al]

Look at the bright side ... now you have to build a new rifle!

[slug]

Oh Al:

You see things so clearly!

The neck expander is marked 356 and that's its diameter.

The neck resizing die measures .369 with my plug gauges.

So, perhaps it's a mis-labelled 9 x 56 M-S.

[44magLeo]

I can't say for sure on those European cartridges, but on one we call the 8 Mauser was not originally called that. It was a 7.9 Mauser.
So perhaps the 8.6 was it's original name but we now call it something else, perhaps a 9 mm Mauser.
That would account for the priming chamber being the same as the 30-06. That's a #2 by the way.
On my 310 tool chart it has 9mm rifle. It lists a #11 adapter die/shell holder, a #2 priming chamber, a 126 muzzle/DA chamber, it just says special under expander chamber, possibly due to a long case, expander plug for jacketed .356, cast .358, and a 238 seating screw.
This sounds pretty much what you have.
My copy of Cartridges Of the world has it and says it obsolete.
In my copy of The Handloader's Manual of Cartridge Conversions, it list's the 9x57 as well as a 9x63.
I think that set would work with that cartridge as well.
The special expander die as listed is also listed with the .375 H&H, so the 9mm rifle may be a long case. On some of the other cases it lists as special are 35 Win,35 Rem, 348 in, this also uses special handles, and the 33 Win.
Not all of these are very long cases but perhaps the long, medium or short expander bodies were the right length so they made them a special length.
If that set is for the x57 case then it should use a medium expander chamber, same as the 7 and 8 x 57's.
The x63 case is very close to 30-06 length and it uses a long expander chamber, why the special. Perhaps some one can fill us I on that.
Leo

[Larry Gibson]

The priming chamber in this set is for a rimless cartridge, the same size as the .30/'06.........So, perhaps it's a mis-labelled 9 x 56 M-S.

That's what it appears to be. Might also, with a little die adjustment, be able to load the 9x57(?).

[NoZombies]

A lot of old euro guns were proofed with the bore diameter being listed, rather than the groove diameter. This could have been set up for one of those.

[skeettx]

Do a chamber cast of the sizing die !

[Baltimoreed]

Slug, I like—‘Real men shoot cast.’

[44magLeo]

I don't think that doing a chamber cast on a 310 sizing die will tell you much. They are just a straight bore up to where it tapers down to the neck size. It doesn't come very close to the body size.
Leo

[skeettx]

Now, not then, when they were an IDEAL company

[Skunk1]

I have one I believe is marked 38L (I think, would have to look again). Never seen another like it. Figured it was 38 long colt but don’t have anything to try in out with.

[bedbugbilly]

Skkunk - trim a 38 special casing down to 38 Long Colt - I have a set of 310 dies that will do both 38 Colt Short and 38 Colt Long - I load both of those cartridges on a regular basis - I use one of several of my Ideal steel tongs that are marked 38 Spl. or 357 Mag - they'll work just fine.

Tak a look at what skeet suggested and the link he provided for information on the 8.6 X 56

I've never run across a set of dies for this particular caliber but I would imagine that they are pretty scarce -

As far as the priming die fitting a 30-06 - remember that priming dies are often interchangeable - the priming die for 30-06 will also work for 8 X 57 Mauser and a few others - obviously if it is with the die set for the 8.6 X 56 but I would imagine that the base of that cartridge is pretty much the same as a 30-06 or 8mm Mauser casing.