585 GMA Express

I have a .585 Hubel Express (Wildcat) made from a case headstamped “.585 GMA EXPRESS”. What does "GMA: stand for? Can anyone post a picture of the .585 GMA Express? Who made the cartridges? How does the .585 GMA Express compare with the .585 Nyati?

Ron, GMA stands for Granite Mountain Arms. That is all I know as I haven’t researched them. My Hubel Express Magnum has the same head stamp. The .585 Nyati has a 71 mm case length and the Hubel Express Magnum has an 81 mm case length. There is a 585 Hubel Express with a 68.5 mm case length, but mine is head stamped Jamison 550 magnum. Bill

Ballard–Thanks for the information on the meaning of “GMA”.

According to information from the source of these Hubel Cartridges (Zac Weighman), there are 3 different .585 caliber cartridges.

I have the following in my collection:

.585 Short Hubel Express–68.7mm Case (Parent case .550 Magnum)

.585 Hubel Express–82.2mm Case (Parent case-.585 GMA Express)

.585 Hubel Super Magnum–91.1mm Case (Parent case-.50 BMG)

There seems to be some discrepancy between what you and I have and what Zac said in a recent email to me. I will contact him to try to clear them up.

  1. What you call the .585 Hubel Express (C/L 68.5mm) is listed by Zac as a .585 Short Hubel Express. Mine, like yours was made from a .550 Magnum case, but Zac says the parent case is the .505 Gibbs. I suspect both cases may have been used by Ed Hubel as both have the appropriate length and head diameter.

  2. What you call the .585 Hubel Express Magnum (C/L 81mm) is listed by Zac as a .585 Hubel Express. He also says the parent case is the .585 Nyati, which is not possible as the Nyati is too short (70.9mm).

Zac knows Ed Hubel personally. I will have Zac contact Ed to get the official names for these cartridges. For what it is worth, Zac and I are working on a check list of all the different Hubel cartridges. I will post it when we are done.

Thanks, Ron. I don’t have the Hubel Express Super magnum based on the .50 BMG. If you find out they are available, please let me know. I am going to check and see if Granite Mountain Arms is listed on the internet. Bill

GMA is located in Phoenix, Arizona and appears to make magnum actions based on the Model 98 Mauser.

OK, my memory is scratchy on this, and it may not be one of Ed’s 585 that I’m thinking of (but it is one of his cartridges), but IIRC he got a great deal on some cases that were mis-headstamped. IE: case was formed as a XXX but the bunter was for a YYY.

Edit: For what it’s worth, my 3 Hubel 585’s carry the following headstamps
585 SHE: (2.713) “Jamison 550 Magnum” My notes indicate that this case has the wrong headstamp
585 HE: (3.240) "GMA 585 Express"
585 HM: (3.607) “L C 8 7” This is Ed’s only bottlenecked round

Tailgunner–OK, so if the 550 Magnum JAMSON headstamp on the .585 Short Hubel Express is the incorrect headstamp for the parent case, what was the parent case?

I note that what Zac calls the .585 Hubel Super Express, you refer to it as the .585 HM (Hubel Magnum). What does Ed call it?

Zac told me you have 2 Hubel cartridges that are the only known examples of the .510 Hubel Express (Later evolved into the .499 HE) and the .550 Hubel Express (later became the .585 HE). What are the headstamps on those.

510 HE “Bell 475 No2 NE.” CL=3.537
550 HE “BB 585 Nyati” CL=3.450

And I probably left the “Super” out due to space restrictions in MY “name” column.

Zac also knows I have another one of Ed’s “one off” prototypes, and that’s of his 2-bores made by trimming a 27x145B case at the shoulder and lathing off the belt.

Tailgunner, I have what was sold to me as a .499 Hubel Express that has a .500 Bullet diameter and a case length of 3.54 in. It has a B.E.L.L. 475 No. 2 N.E. head stamp. I assume it is really the .510. Bill

Bill-There are two versions of the .499 Hubel Express.

.499 Hubel Express, Version 1. Used a B.E.L.L. .475 No.2 N.E. headstamped case, 500 gr. bullet, 3000 F.P.S.

.499 Hubel Express, Version 2. Used a B.E.L.L. .450 No.2 N.E. headstamped case, 500 gr. bullet, 3000 F.P.S.

The big difference between the 510 and the early 499 is that one is built around 50cal rifle bullets (.512 nominal) and the other is built around 50cal pistol bullets (.499 nominal). It was a bullet cost/availability thing. Other than mine, the rest of Ed’s 510 cases were resized into 499’s.

The other thing you need to understand, is that I’m the guy that introduced Mr Hubel to Zac and the cartridge collector world.

Yes I think the short 585 Headstamp with the 550 Magnum headstamp has to be a mistake as the 550 Magnum has a rim diamter way smaller at only about 0.575 while the 585 HE’s are at about 0.637.

Cartridgecorner–Don’t let the presence or lack of a belt on the parent case confuse the issue. Ed Hubel is a Master Machinist with all the equipment to do whatever he wants to with a case. He can add a belt (or remove one) at will. He can straighten a taper or change it. He can add extracter grooves and change head sizes, both larger and smaller. He can use a CNC lath to thin a case wall if needed after cutting off a thicker case. There is not much he can not do when when he wants to make a new case type. Also, remember, this man makes guns from scratch for each of his cartridge types.

Yes I know that is true for sure, but for Jamison to do the same I think is unlikely. It is more the rim diameters being way off that are my points. I chanhed the belted portion of the message as it is a “Possibility” for sure.

Ed here-- I made the first 585HE belted cases from Bertram Nyati basic brass
years ago, it came to me 3.3" long to work with. It had the regular
Roo type headstamp. Bertram also made same size
cases as a basic long case for GMA, stamped with their
585 GMA Express stamp. They made their 585 GMAs from them.
I got a large batch of these after the others
were gone and made them all into my 585HE also.

Now about the Jamison Gibbs size brass stamped 550 Magnum.
They’re made as 505 Gibbs size. A straight long basic case when partly done,
before being formed into the necked Gibbs case.
At the time he was making a run of 505 Gibbs cases, he was also doing
a run of 550 belted magnums. These 550 cases were the idea of RNS on the
Accuratereloading forum, and were just the 460 Wea straightened out all the way
and I made the first ones for him from 460 weatherby cases. And posted pics
and sent them to him. As for the types of actual 550 Magnums out there,
that are Weatherby body size, there will be home made ones, stamped 460 Weatherby,
500 A-Sq, and manufactured 550 Magnums from Jamison.

Someone at Jamison got the part of run of Gibbs basic straight cases mixed up for
stamping and headstamped a whole bunch of Gibbs brass 550 Magnum and
sent them to RNS , then later the regular Weatherby based 550s were stamped
and delivered. The regular 550Mag is 3", the mis-stamped ones about 3.25",
same body size as a Gibbs basic case, just straight and not stamped right.

A while after this I made a 585SHE from 505 Gibbs, which was 2.7" long, straight,
and head-spaced on the mouth and the guns extractor, like Ram and B&W cases.
I got a few of the mis-stamped ones and also made some into my
585 SHE cases. Then later I got some of the Gibbs cases that Jamison had
made extra, but not stamped yet, and made 585SHE and put my stamp on
a whole bunch of them.

Hope this helps, so you know what you got.Ed

Thank you Ed, for providing the proper time line and history of these cases.

[quote=“RonMerchant”] . He can add a belt at will.
He can … change head sizes, both larger and smaller. .[/quote]

Hello Ron,
!!! Are you sure you are not exagerating a little bite ???
If not I am curious to know how to do these tricks.

Using a lathe, a grinding machine, an electro erosion engine or a CNN allows you to take out material, not to add some

You can adding a belt to a case by swaging the case or soldering a brass ring on the base that can be turned later to the proper diam.
You can also create a belt turning down the base leaving a “step” . My 700 HE samples , from 50 BMG cases, have been turned down creating a belt.
They have .795" diam belt and .770" heads, whereas the 50 BMG case measures .795" at the base

[quote=“Pivi”]You can adding a belt to a case by swaging the case
[color=#0000FF]have you already seen that ???[/color]
or soldering a brass ring on the base that can be turned later to the proper diam.
[color=#0000FF]first this is not a simple operation using a machine and second have you already seen that ???[/color]
You can also create a belt turning down the base leaving a “step” .
[color=#0000FF]this is not making a head larger than the initial one[/color][/quote]

I have not performed swaging a case to turn it into the belted form, but I suppose that could be done if the brass is thick enough. Swaging is usually done to reduce the base diameter slightly, and generally requires a hydraulic press to accomplish.

I have never soldered a ring on a case to make a belt, but I have tightly fitted a brass ring/sleeve (cut from a .40 S&W case) over a .30-30 case base as part of a conversion to .303 Savage (which has a 0.02" larger base diameter). It’s not worth the effort - it’s much easier to wrap a few turns of masking tape around the .30-30 head (to centralize), then fire-form it in the .303 Savage chamber. After FL resizing, of course.

Donnelly’s “Handloader’s Guide to Cartridge Conversions” (which by the way is a superb reference for case dimensions of a huge variety of standard, obsolete, foreign, and wildcat cartridges) does mention both swaging belts and soldering on a brass ring, which is simpler. In both cases, the case belts must be afterward machined to correct final dimensions in a lathe.