It would be nice to generate a brief list of gunsmiths who have experience building 585 or 577 bolt rifles.

My 585 was built by Franz Bryner in Ogden, Utah.

mine... like most of my others...
built by...Poppa Bear....
aka
Jeffeosso

Alan Swan from Brisbane Australia started on mine, and after 10 months had caused more hassles than anything.
Mark White of Melbourne completed it.

Don't embark on your fist 585 with gunsmiths who are also embarking on their first

Karl.

McGowen Rifle Barrels built my barreled action (Pac-Nor Barrel).BTW.Gunsmith Dennis Olson has a lot of experience building 585s.

Bob De'Vries of Melbourne is building both mine and my mates. I have to confess Karl it will be his first shot at it. This is why I told him to do my mates first . Mike 375 put me on to him.

PC,
I'd be surprised if you have any problems with Devries. Also would you mind if I mailed you and asked what he costs?

Regards,
Karl.

Karl and PC,

I have a .585 project in it's infancy. I have a barrel blank, reamer, headspace gauges and some cases. I also have a number of actions (Vz24, ZKK-601 and M17) but would be very interested to know what actions you used for your projects and if you have any suggestions or comments on action selection for such a monster cartridge.

By all means Karl.

Robert,

I am using a ZKK 602 Brno action and my mate is using a 602 as well.

We were going to use cz 550's but at the time we were shopping for actions the 602's were all that was about.

In some respects I would have liked to use the cz 550 as it would match my .416 Rigby exactly, but on the other hand Ross Seyfrieds original experiment was completed on a ZKK 602 so I am keeping to his original rifle. Besides the safety I hope the ZKK 602 action is not giving to much away in regards to features that the 550 action might have.

The .585 can also be done on a mauser 98 but from what I understand a lot of work is required to make this work. 500 grains has his built on a M70 and he states his works well. I would do it on either the ZKK 602 or the CZ 550 if your on a budget like I am.

I also want to add that I can't see why if one downloaded the .585 a little say to 2300-2400 fps with the 650 gr woodleigh softs and solids could it not be classed as a legitimate African cartridge rather than "a just beacuse it can be done project"??

I built mine. It works ! It was a pain! Why down-load when you can get max?-Rob

With respect to actions, I still think the cz550/602 are the most appropriate actions for this cartridge. I'm sure a good 1917 enfield will also work. If you use a M70, my read of the mag box is it will be a two shot single stack only. One of the problems encountered with the 585 NYATI is that the Bolt rim must be opened up to .640. On bolts with diameters of .700 i.e ( the CZ550/602 this leaves precious little metal left on the rim. The bolt face also need to be recessed about .010. The thin bolt rim must be rehardened after it's opened or the thin rim will tear off. The NYATI is a fat cartridge so the action requires alot of rail work ( not for the faint hearted) and the feed ramp must be "U" shaped and polished and the little CZ "wings ground out". Only then will these actions feed the NYATI. Oh by the way, it's still only one in the pipe and two down. A new follower and mag bottom will be needed for more.-Rob

"If you use a M70, my read of the mag box is it will be a two shot single stack only."

Yup.

Rob how much better is the CZ 550 than the ZKK 602 leaving aside the safety and trigger differences ??

In regards to loading down Rob, I am thinking if I want to blast a heap of ferals I do not want my eyes falling out of my head and I thought that by using 650's at 2300 fps that might help.

The 602 is better because it has a .720 nominal bolt body diameter instead of .700.

Has it really 500??, I thought they were exactly the same.

Were do you measure the bolt Diameter from do just put the micrometer across any point of the bolt??

Put the micrometer across the bolt just behind the bolt face. Usually you will find the measurement just below nominal specs due to polishing. For example, a model 98 or model 70 will measure .697 instead of .700.

The great advantage of the custom magnum mauser actions is their .750 bolt diameter which handles the Gibbs case head (.640) just perfectly. But those of us who do not intend to spend $3500 for an action in the white have to take other steps to make things work.

I had always been under the impression that the 585 was rebated to the 416 Rigby case rim size.....Mike

It can be Mike, there are advantages for leaving it with Gibb's Rim and Advantages for rebating. From what I can gather it is a better proposition to leave it with the .640 rim. I have read why but have forgotton.

Someone else might be able to expand on that.

PC,
I know of some smiths who prefer not to open up the CZ bolt to gibbs rim. I'm no gunsmith myself.
Other reasons... less trouble finding a shell holder?
I will ask my brother to post on a picture of my case.Personally I think the rebated rim suits it. Like a 500 jeffery on steroids or something

Karl.

Yes Karl if it had the Rigby .416 rim I could prime in front of the T.V

Instead I have a gibbs .640 and I have to prime on the bloody press beacuse the Gibbs shell holder will not fit My RCBS hand primer tool. The .416 Rigby shell holder is as large as it will go.

Robgunbuilder may be able to tell us which was beter the gibbs or Rigby Rim.

Yes your enlarged .585 case would look good with the rebated rim, some of us need to make our cases look as big as possible

mike375

The problem with the 416 rigby size is that the rim is so severely rebated that reliable feeding cannot be expected. As the cartridge sits in the magazine, the 416 rim will be down from the top of the cartridge by quite a distance, tempting the bolt to ride over the cartridge instead of picking up the rim.

That is also what my smith said. I re-call asking him this question which rim size should we go for. It clearly makes sence. Thanks 500.

500 grains is absolutely correct the .590 Rim version of the NYATI will only feed properly with a single stack magazine. There are quite a few of them out there that people have tried to get to work with the .590 Rigby boltface and staggered magazines only to have incessant feed problems due to the severely rebated rim which is easily overridden by the bolt.. I saw one at the Safari show and the owner admitted to the possibility of feed problems in it. Duh! It only cost about $5000 too!
The .635 case head variation ( the one we are all using I believe and which I have on order from Horneber)solves this problem but requires a .640 boltface. I don't have a ZKK- 602, but I thought its bolt diameter was the same as the CZ550 or .700. I know the BBK-02 bolt diameter is .720 and this would be an even better choice IMHO. However, with proper hardening there is no problem with building a NYATI on a .700 bolt.-Rob

Rob,

How much better is the 550 action over the 602 (trigger and back ass safety aside) have I chosen the right action??

OK, maybe I have the BBK and the ZKK mixed up.

PC,

With a little work with my Dremel I got my 470 NE shellholder to fit my RCBS primer tool. Just use a cut-off wheel to remove enough of the metal so the shellholder fits.

Yep, I believe Robgunbuilder got it right.
I recall measuring the ZKK-602 and the CZ-550's that I have. Both are the same 0.700". My BBK-02 has a 0.720" bolt. It is a 460 Wby.

Mitch did his 577 T.rex on a BBK-02, and with it's even larger rim (0.688"), there is little to spare.

I actually acquired 60 pieces of the Bertram 585 Nyati 3-1/4" basic brass before I knew any better. Horneber is the way to go.

I whimped out on the 585 Nyati, deciding I could make do with my .510 bores as my dinosaur rifles/stunt guns. 10#10oz without a brake and using express sights makes the 510JAB/500A2 on a ZKK-602 tolerable to carry and shoot. 600 grains at 2400 fps is enough for me. I also have a big screw on brake and a scope that will get it up to 12.5 lbs. if I can ever find a gunbearer.

If I ever decide to turn the BBK-02 into a 585 Nyati, I would go with the .635" rim. Just for laughs.

Hey! I'm getting too old for this stuff! You young whippersnappers run along now and have fun, while you still have vision in both eyes.

DaggaRon,
I think you made the right choice for hunting purposes. The 600 grainers @ 2,400 fps is all I care to use, also. My .505 is giving a moderate 2,350 (corrected fps) and, with no brake, it is about "max" for good work, afield.

I like following these 585 and 500 threads before a range session with the 375. Almost feel like I don't need to go and just shoot it in the house and use one phone book as backstop

Although I say that in jest there is some truth in it. Over the years I have noticed that shooters most likely to have problems with 375 recoil are those who think the 375 is a cannon. Others who may not have owned bigger but whose interest in big bores has meant they are very consiously aware of the gap between the 375 and 460s plus always seem to find the 375 easier to use than those who think the 375 is a cannon.

Mike

Mike,

My first centerfire was a Ruger M77 MkII ultralight in .308, and I shot it with the factory hard rubber pad, in a tee shirt. I'd burn 40-50 rounds at a session, and at that point in time, a 375 H&H Certainly sounded like a cannon. After moving to AK, I had the 35 whelen ackley built, and found the recoil a step up, but not a huge deal. Then I picked up a 458 lott, just because I was curious about powerful rifles. I learned that if one wants to shoot a big gun, so long as the gun won't physically harm you, there is no reason one can't shoot it, and shoot it well. I keep debating a 585 Nyati, but I'm still waiting on my 500 Jeffrey, and just may be satisfied w/ 600 gr bullets @ 2400 fps.

Paul,

If that 500 does not have a brake it should be a totally fulfilling experience.

Mike

Efryman,
good idea with the dremel I might alter my shell holder.

I looked into getting a Oly-arms action for my .585 but the wait would have been to long, is hard for us Ausiies to get anything over here, it takes ages "Tyranny of Distance I suppose".

Nickudu and Mike375,
You are wise men.

Paul H,
You are getting there.

Daggaron, if I owned that BBK-02 action of yours I would definitely chamber it for the .585, your wasting good useable bolt face

PC,
That was my idea initially. Now, whenever I get the urge I just smack myself in the face until I snap out of it. These urges are getting less frequent as the hair gets more gray. Middle age crazy should be done soon. People do stare sometimes when I walk down the street slapping myself. It is kind of embarassing sometimes.

You never know when mine is finished I might have wished I had your intelligence and pulled up at 600 gr at 2400 fps

After much carefull thinking and experimenting, I believe there is ABSOLUTELY no reason not to use a .700 bolt for the .640 Boltface for a NYATI or 505 Gibbs. In truth, I'd save those BBK-02's for a T-ReX. Remember, A-square ( now all spit) used the 1917 Enfield action with a ..697 bolt for the T-Rex and got away with it. I've never actually seen the bolt face on one of these and perhaps BMG who has one could post a picture.
Whoever does the conversion simply needs to be able to make the cut( grinding with carbide is better) and deepen the boltface about .005 and then re-heat treat the bolt rim. I obsessed over this for a week then just went and did it on my CZ550 and the whole thing took about 1/2 hour including set-up( I'd post the pictures, but then you all would see how simple it is and I'd lose my mojo). I doubt it makes any real difference if you use a ZKK-602 or a CZ550. The big difference for me is that I can buy new CZ550 actions and I would have to buy an entire ZKK-602 and then have to tear the gun apart. Those guys use locktite on their barrels and it take a pipe wrench and my 17 year old son to get them off. The only other problems with a NYATI are the need for a good solid second recoil lug and the most important thing which is the custom reamer with a .614 neck rather than the .609 neck that everyone else uses and then has enormous trouble with. -Rob