While the 585 does seem like a spendy beast to feed, the answer is simple, cast bullets, they can handle 2000 fps, and thats plenty with 750 gr pills.

Aye carumba, gotta make sure Santa puts that 12X36 lathe under the tree

I have a 585 nyati but I do not have the case dimensions with me at this time. Keep in mind that the 585 nyati has a rebated rim (505 gibbs size), almost no case taper and a teeny tiny shoulder. I suspect you would have headspace problems if you built a 585 by necking up the 505 gibbs case.

Yeah, that's my conclusion. My post was kind of a thinking out loud, and then an oh, maybe I should just go with the 585 Nyati. If you could provide some specs it would be greatly appreciated. I was re-reading a text version of Seyfried's article I was sent, and there were no case dimensions. I also don't know of any sources on the web that would have case dimensions.

Hmm, seems like a good project for this group. We could put together a case spec page and have Saeed post it under the load data web page. It would be nice to have a list of case dimensions, as it seems to be a frequently asked item.

From reading the old articles by Ross Seyfried on the creation of the cartridge, and from measuring a piece of Bertram basic 585 Nyati 3.25" brass I get:

Case OAL: 2.800"
Rim: 0.635" (same as 505 Gibbs)
Case Head: 0.655"
Shoulder diam.: 0.650"
Neck diam: 0.605"
Shoulder: 0.045" or 0.0225" per side
Shoulder angle: 30 degrees per side
Neck length: 0.500"

Does anyone else have any more details?

The 585 Nyati and the 505 Gibbs can both be made from the 577 Nitro Basic case made formerly by B.E.L.L., I do believe. I think the case body was made heavy and to make the 505 Gibbs out of it the body had to be turned down as well as the rim to that O.635" diameter.

The Nyati rim is rebated to 0.635" from a diameter 0.020" bigger at the case head: 0.655".

A regular 505 Gibbs case would seem to be too small to make enough shoulder for the Nyati.

As Mike375 implied on the other thread, you will be fine with the Bertram stuff for the 585 Nyati for any load a reasonable human would want to use in an unbraked portable stopping rifle. Horneber makes excellent 585 Nyati brass ready to load, if anyone could find him by telephone or email.

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DaggaRon
RAB

[This message has been edited by R. A. Berry (edited 12-07-2001).]

I would like to think the Nyati has 30 degrees per side as its shoulder angle.

Where is Ross Seyfried when you need him? He has so much class that he would fit in well at accuratereloading.com.

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DaggaRon
RAB

On my fired 585 cases, the shoulder so small that it really does not matter how may degrees it is. Fact is that it's just a little nub that you can feel with your fingernail. However, it is a sharper shoulder after fireforming than before.

I bought a pre-chambered barrel from pac-nor, so I guess somebody could call and ask what degree shoulder their 585 reamer has.

I bought my dies from CH4D, and he has a drawing for the 585 from which he made the dies. Again, a phone call could resolve the shoulder angle issue.

But in fact the shoulder is so small that I think 10 degree and 40 degree shoulder ammo would be interchangeable.

Also, just a reminder that Bertram brass is soft as dog turds (that means as soft as A-Square brass for the uninitiated). It sure would be nice if that Hornberger guy would answer his email and ship some brass out here!

Thanks for the specs.

500,

Is the plastic elastic silly putty Bertram brass good enough for 750's @ 2000 fps?

Don't suppose you'd be interested in trading a 500 Jeffrey (star, good brass) case for a 585 case?

Yeah, the brass works just fine. But it feels weird in the dies, and I have had a few sticky cases even at low pressure (2250 fps). Would you really want to go down to 2000 fps? The recoil is not that bad at 2250. I am good for 16-18 shots at a whack, although a dose of tylenol is needed after that. Lately I have taken to ingesting Ibuprofen BEFORE I shoot the 585.

I would be happy to trade a case. I will send you a fireformed one so that you get the dimensions right. Email me your address.

I often wonder if a case had a shoulder that was no bigger than the brass thickness, would that kind of make like a belted case but with the "belt" being at the shoulder.

Mike

I'll bet D'Arcy Echols could give you an estimate, offline if not online.

Ross Seyfried himself said the 585 Nyati may be a "nightmare," whatever he meant by that.

He described firing it for the first time in a rather light unbraked gun. He said his head was sucked out of his shooting glasses and his earmuffs ended up clapped over his eyes. Sounds like footage of one of Saeed's guinea pig "heroes."

I have given up on it because your beloved 500 A-Square does all that a bolt action could be asked to do, and more.

Instead, I am scheming about the side by side double in 470 or 500.

Whether bolt or double, bigger than half inch bores either kick too hard or weigh too much to be practical hunting rifles. No need for anything bigger really, even as a "stopping rifle." After .510" it is just psychology and sadomasochism. Oh! It hurts so good!

But, if it is just an exercise in rifle building, have at it! More power to you.

(Psst! If you find out how much, email me, but don't let anyone know that I am interested. I must keep up appearances of sanity, you know.)

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RAB

[This message has been edited by Roger Rothschild (edited 12-10-2001).]

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RAB

Ross Seyfried does not use his computer for anything but word processing, refuses to do e-mail or internet. His single phone number is for voice, answering machine and fax.

He is a first class gentleman. I've been in regular correspondence with him for most of this year.

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RAB

quote:

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Originally posted by DaggaRon:

Ross Seyfried himself said the 585 Nyati may be a "nightmare," whatever he meant by that.

He described firing it for the first time in a rather light unbraked gun. He said his head was sucked out of his shooting glasses and his earmuffs ended up clapped over his eyes. Sounds like footage of one of Saeed's guinea pig "heroes."

---

Ron,

I gotta ask, why the change in handle? Also, Seyfried's comment was in regards to the 750 gr 2500 fps load, not the 2100-2200 fps level. I have an electronic copy of the article, here is the section you're referencing:

"To the end of determining a margin for error and satisfying my curiosity, I continued to increase the charges until I either ran out of case capacity or began to see signs of maximum pressure. With a case full of 4350 and 750-grain bullets, velocities were over 2,400 fps. Changing to Hercules Reloader 15 powder I hurled the big 750s over the 2,500-fps mark with energy in excess of 10,000 foot-pounds and a Taylor Knock Out number of 158 (compared to K.O. of 86 for the .460 Weatherby and 150 for the .600 Nitro). My load development was done with the rifle held in a machine rest and fired by remote control, for safety and to avoid recoil punishment. I fired one round loaded with a 750-grain bullet at 2,500 fps from an 11 1/4 pound rifle offhand, from my shoulder. It was an unforgettable experience. In the fraction of a second when the rifle was in full recoil, I thought it had hurt me. There was the monumental feeling that the rifle had gotten all over me. I couldn't see and the whiplash felt like a giant was trying to pull my head off. The recoil sucked me out of my shooting glasses and clapped my earmuffs over my eyes, accounting for the blindness. After taking off the blinders and checking all body parts, I found I really wasn't damaged. But it's an experience I don't care to repeat.The recoil approached that of a 4 bore, but with much higher recoil velocity. This kind of horse-power would require a 16 to 20-pound rifle. This of course defeats the purpose of the project. The Nyati is supposed to be light, handy and manageable. With 750-grain bullets it will break both shoulders on the biggest elephant. Why tamper with success."

I must be sick, I'm undaunted and am seriously considering a 585 Nyati as my first barreling project once I get a lathe. With Pac-Nor offering pre-chambered barrels, it saves the reamer cost.

DaggaRon? Because I want too.

I have waxed and waned on the Nyati thing. A light and handy 470 Nitro double is my fantasy now.

My 510 JAB is perfected. A 600 grain bullet at 2400 fps is enough for me.

Call me a wimp, I don't care.

PS: Recall that I have shot a 0.472" 3-shot group at 100 yards with Mitch's T. rex, using 900 grain Woodleighs and 160 grains of H4831.

Also a 0.591" 3-shot group at 100 yards with 750 grain Woodleighs and 182.5 grains of H 4831.

Also a 0.665" 3-shot group at 100 yards with 750 grain Woodleighs and 182.5 grains of VV 560.

I would have shot 5-shot groups, but that would have given me an even worse headache!

We used no shot bags at the bench, just Mitch's Past pad.

BTW, I can also shoot 750 grain target bullets to 1000 yards with the 510 JAB, and ammunition components are no problem to obtain locally. That is MY IDEA OF A BIG BORE BOLT GUN/FUN GUN. To each his own. LOL...maniacal LOL...
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RAB

[This message has been edited by DaggaRon (edited 12-11-2001).]

It isn't supposed to make sense. I mean, I have the 35 whelen AI which suits essentially all of my hunting needs. I had a 458 lott, but sold it to fund a 500 Jeffrey, and John Ricks convinced me to build a 458 in addition to the 500. I'm still waiting on both barreled actions, but still am not satisfied. I don't have a 416, and the 416 Howell keeps me intrigued. I also have a nice 460 gr 475 mold, and think about a 475 lever gun, or a 470 NE on a Ruger #1.

With all those big bores in mind, I still think about the 585 Nyati. I'd primarily shoot cast out of it, so costs wouldn't be too bad. Yes, the Jeffrey can be loaded to sufficiently obscene levels, ie 600's at 2400 or more, and 700+ gr mil surp at 2200. Should be good enough, but the 50's only make 1/2" holes, not .585" holes Yes, it is a disease, and I do believe I can stop at .585".

1. action size: I don't want anything based on the 50 BMG actions, and I cannot justifying $8-12K for a top end super big action. So I just don't know what action I could base it on.

2. penetration: Unless velocities are kept in the 2200-2300 fps range, the .620 will lose a LOT of penetration compared to the 585. And at that velocity, it will kick like a hydraulic ram.

How fast can the Nyati push the 900 gr bullets? Assuming 2200 fps, to match that with a 620 rimless would require a whole lotta lead, or copper

I know it is not supposed to make sense, but it is supposed to be fun!

I don't like muzzle brakes nor guns heavier than 12.5 lbs (scoped, loaded, and slung) to lug around all day.

Furthermore, I tend to think the .510 caliber 570 grain FN by GSC at 2500 fps will out penetrate any .585 bullet around.

And there are so many other .510 caliber soft, solid, and target bullets available!!!

Now boys, remember that sometimes size doesn't count, rather it is how you use it.

This is sage advice from one professional small boy to another.

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RAB

What I might lack in one department I can certainly make up for by building large bore custom rifles. Even though size may cause me to give up a bit of penetration, I still like the idea of size.

Paul,

I have only pushed the 900 grainers to 1879 fps and the recoil was very punishing - worse than 750 grains at 1330 fps. I need to do some more load development to get 900 grains in the 2200 fps range. Frankly I am not sure I can do it. Probably 2000 or 2050 fps is about it. About then I will need shoulder replacement surgery.