I have been talking to Ed Hubel again...as usual the mentor gave me several shall we say, interesting things to mull over the weekend. As everyone here knows, I am agog over the possibilities of the 505 Gibbs FL cylindrical case.
I am, as well, getting some serious level inquiries from two different rifle companies, one of whom already builds 505 Gibbs, and another who is looking into the matter.
So, I let my imagination run amuck picking Ed's brain...finding out that he also looking at the same options on that big mother of a case. We have come up with some intriguing offspring options.

1. Do a "Hubel" with the case and add a rim. A basic 550 Gibbs Flanged version of my brainchild that would
use the same dies and be appropriate on a double rifle.

2. A 28 gauge from Purgatory. A 28ga WW shell I have here at the desk mikes .680" on the rim (vs .640 for the
Gibbs), the case ahead of the rim mikes .613" (vs .640" for the Gibbs), and is 2.397" (vs 3.20" for the
Gibbs) OAL. The dimensions are close enough Ed says he can swage the 505 down easily to those specs, and
add a rim ala the 12GA FH. It would make up on an Enfield/M30 Remington as a version of the 28gauge rifled
slug gun. The new bunt die could read "Jamison 28GA Magnum" and be legit anywhere. You could, if you
chose, even shoot 28ga in it.

3. The cylindrical Gibbs measures .630? or so OD at the mouth and .601" ID at the casemouth. Add a rim on
that and make your own version of the .600NE. .600 Jamison-Gibbs Flanged Magnum.

I very much respect the informed and experienced big-bore members here. Anybody got any thoughts on one or all of the above?


Rich

Oh yes, almost forgot. I am final design stage on a family of DG cartridge. A .450, a .475, a .510, and the .550 and maybe a .585 and/or 600. Whaddya think RIP?

Rich

Rich,
Marc Jamison has already done the 28 Guage From Purgatory!

Have you not talked to him about it?

It may be called something else besides "28 GFP" but Marc told me he got some high velocities with it from lead slugs and shot loads.

He has some beautiful 2.75" long 28 guage magnum brass.

Is that about .550 caliber for a 28 guage slug?

I would rather see you make a po' folks 600 out of 20 guage brass.

Lets just call that the 20 Guage From Shangrila (20GFS).

And don't forget the 10 Guage From Valhala (10GFV), a favorite of Odin and Thor, when they are not chucking spears and hammers.

Though didn't Rigby do a .775 caliber double rifle based on the 10 guage, way back?

Sounds like some more good entertainment on the way, and you don't need any encouragment from me. Keep us posted.

twisted minds think alike...

thanks for the pm rich...

i was bouncing around in my head the last 3 days the 577 version of yer 550 watchamacallit (you got rips disease of renaming carts )

i know more people are gunna make 550 bullets but i thought to myself...hey wadabout the 577

glad yer 5 steps ahead of me

call it the 577 from hell!

no matter what you put at the tip of this case as long as it can hold together it should penetrate two elephants lengthwise.

i must say the 20 and 28 g.f.? are great ideas!

it is true the saying there is a fine line between a hobby and a mental disorder...guess which side we are on

are their cheap 20 and 28 ga guns that can handle this level of frankensteining???

blackpowder loads in these mini 12gfh's would be a hoot!

may the big bore gods be on yer side...

Boomer,

there is a line of well made, including a Greener crossbolt, spanish shotguns. A friend is turning a 12ga into a SxS 45-90 for everything in Idaho. I have held a 20ga, and it would be a snap to make a 550 Flanged Magnum on that shotgun. I plan to make a cartridge case with a rim that would utilize the same dies and reamers, just cut the rim after you headspace the standard 550 Gibbs (whatever) and make the rim a bit thicker if you wish. Ed Hubel thinks it would be a simple task, ala his 12GA FH on a smaller scale. He also thinks the cylindrical case, as is, with a rim would be a less expensive option to the 577NE or 600NE 3 1/8". I tend to agree.

We are getting some interest from the big boys. Neal thinks a major player is going to chamber his 550 Magnum in their Safari Magnum line...hint!
I have been in contact with Hornady, and they have offered to make the 500 Gibbs reloading dies for me at no charge, and would I allow them to make a few extra sets. Yeah Howdie!!!!!!! I have offered to provide them with my initial loading data, and they have accepted my offer...may be doing some of their own ballistic adventuring with a pressure barrel. I have given my thoughts on bullet weights and shapes: a 600gr spitzer like the 450 Dakota carries, and a 750-800gr softpoint and solid, both blunt nosed or NF-style.

So, things are looking very "UP" here. Our forum does get reviewed by the big boys R&D department.

Take care,

Rich

Rich,
Sounds like some real shaking and moving going on.

With Neal having gotten the ATFE to certify his .550 Magnum cartridge design as a "nondestructive" or sporting whatever, and CZ having the namesake 550 Magnum action that it fits so well, it seems a natural for getting that up and going. Build it and they will come ...

Did you say you were doing a 500 Gibbs with Hornady? Is that one of the new Jamison Gibbs line that you are proposing? Would that mean Hornady will be making .505 Gibbs basic brass?

These are very interesting times we live in.

Alas, I shall remain a pedestrian with the Rigby based RIPoff line I am perfecting. Then I am going after the Big Five, in my Field of Dreams.

Hornady has kindly offered to make me 550 Gibbs-Jamison dies, just for the experience and encouragement. They are interested in things like this, and I am glad they are. There could be, by next spring, a family of four, perhaps five in this line up. A 458-475-510-550, and a 577 or 600. Although, the 577 is more likely, unless the 600 gets a rim for double SxS rifles. Neal, again, deserves the Kudos! for getting all of this rolling. I just fell into it while we were talking about his awesom, practical, .550 Magnum. I see some serious, intelligent design in what you are doing. Intelligent design = intellignet designer.

Rock on RIP

Rich

who makes 577 flat nose solids???

the 577 will be the most unique since the 550 magnum cant go up to that cal...

how will the 577-505 gibbs improved aka 577 kayser express compare to the 577 t rex???

Good-lor-deliverus-good-lor-deliverus-good-lor-deliverus ...

I hear the night jar and see the Southern Cross before me ... am I hallucinating or does sumbuddy really think a 577 Gibbs is feasible?

A .550/.505 Gibbs, sure.

But a 577 Gibbs, which would be a .585/.505 Gibbs ... With a .585 bullet???

I have the cylindrical case in my fat little fingers. .640" at the rim and base. Lemme see now, .020" taper to .620" at a shoulder area, .020" shoulder per side, leaves me .580". Would that be enough neck to headspace properly? OR improperly? That's about where I am at with the 510KX, a bit thin you think RIP? Going for four with the 450-475-510-550 will keep me busy for the next year, even assuming I just switch the barrel for each job.

Rich

IIRC, when I measured my Jamison .505 Gibbs brass it was a little less than the .640" nominal/CIP/Birmingham Proof House MAX specs. It was about 0.635" at rim and head. It has to be an easy slide into the hole for a DGR, eh?

You will have less shoulder than the belt step on a .375 H&H. Less than 10 thou, about 0.0075" per side on the shoulder if you are realistic about the actual brass diameters and neck thickness, and tapers.

Must be some reason for Nyati and T.Rex brass.

When we are getting down to quibbling over .005" that is too "borderline" IMHO.

Rich,
just to help out

475x505 is the 470 royale

you cant' put a .585 bullet in a gibbs case, without belt or rim. the brass thickness is about all there is to "headspace" off.. and if you crimp it, it's gone.

The 550 mangum and express are listed ass sporting cartrdiges. This may seem subtle, but it is NOT an exception for a DD..

jeffe

thanks RIP and Jeffe for the advice and data. I was just thinking...

Rich

on the other hand, I have been watching a double rifle go together in 45-90 at the shop. I do NOT have a problem with spare time the next three or four months converting a good 20Ga SxS to my own 577 or 600 Gibbs Flanged.

Rich

.577 wouldn't have shoulder for headspace
in Gibbs casr, i made my one off a kind
585HE from Nyati long basic case which has
.020 more diameter to work with. Mine is
belted straight case. Now for 28ga project.
If I can get the cases we want to use to
hold a rim on, for resizing purposes and
extraction from the chamber, we will have a
long 3.2+ inch 28 GA. Stamp barrels
28 GA 3 & 1/4 inch.The legal definition.
And chamber will fire any shorter 28 ga case.
And barrels available from all the ones set up to make 550 barrels.Bauska has good price.
No paper work, it is just a 28ga shotgun
caliber. And the Gibbs 550 case Rich is
making won't chamber, so no one can't call it
his rifle caliber.
Name- What's in a name. As far as name
goes , credit for making the 28 GA
a famous caliber, would suggest
28 GA CH............Ed

thanks Ed,

I was just "what if-ing" on the computer keyboard.

Rich