What is the 3" version of the Nyati...?

Dosen�t the Nyati have a case length of 2,85"...?

How high velocity is possible to get whit 750/900 grain bullets in the 3" version...?

Were do you get 3" version cases...?

Yes OK the .585 is usually 2.85". The 3" version is sourced from the same brass as the 2.85" meaning it comes from Bertram at around 3.2" if I remember correctly and then you run it through your trim and file die etc. If you had the 3" version you would have a custom set of dies made for it. There is a bloke who writes on this forum named Karl who has built the 3" version I think he gets a couple of hundred fps more than the 2.85".

I was considering building a 3" version but it would have been more work and the whole project will be enough expense and work any way.

Regards PC.

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PC,

How high velocity is possible to get if the 2,85" can do 2550 and you say that the 3" can make couple of hundred fps more...?

A couple more 2600-2700-2800-...?

Does it have more power than the Tyrannosaur....?

My reamer dimension for the NYATI is for a case which is 2.815 inches long. I have Ross Syfrieds original reamer dimensions sitting here in front of me and they state a distance from the boltface to the end of the neck of 2.815.If you try and cram a 2.85 inch case into this chamber it will go Boom! I trim my cases to 2.800. With that said you can easily make a 2.5 or 3 inch version by running the reamer in more. An advantage is that you would not have to trim the Bertram brass nearly as much as for a 2.8 inch case. However, now its custom headspace guage and custom reloading die territory. The magazine of a CZ550 will take a larger case. The 2.8 will dish out all the power and recoil anyone in their right mind could ask for. Why bother?-Rob

Rob my dies arrived next week and the gunsmith has the reamer. He wants us to provide him with loaded rounds before he begins work. I did not exactly know what length the cartridge was but my CH4 dies measure 2.9" if the dies are screwed to the shell holder. But what ever length my trim and file die is will be the length my chamber will be. I suppose it will be of the original dimensions. I agree with you Rob that the 2.8" has all the horsepower one really needs. But then again it is not about neccesity is it

Overkill, you would have to ask Karl for the exact velocity. I am pretty sure he told me once he was getting 2700 fps from the 750 grainer. I could be wrong however. The 3" version would be the equal of or slightly more powerful than the .577 T-Rex. Really the 2.8" version is only a tad behind the T-Rex.

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PC-The dimensions of the reamer are the most important aspect of setting this cartridge up properly. The reloading die info will vary from manufacturer to manufacturer and won't help much. However, make certain your trimed cartridge case length is at least .010 less than the reamer dimension or you will have a potential bomb on your hands.Please do not overlook this!
Let me suggest to you the following procedure: Have your gunsmith get a copy of the reamer dimensions from the manufacturer and tell you exactly what the boltface to case mouth dismension is. He should also confirm these measurements himself in case of error. This almost certainly will be 2.815 inches. Have him chamber your barrel and headspace the action. Supply him three cases which have been formed in your dies and trimmed to .010-.015 shorter than the case OAL. Don't try and seat a bullet yet as they won't fit and will distort if you try. Anneal your brass using a propane torch. Have him fireform these cases in your chamber with 25grs of bullseye and a cream of wheat filler to blow the cases out to the chamber dimensions ( neck-.6095 tapering to .6085). Take these cases and outside neck turn them a few thousanths or until they will chamber with a bullet seated in the case mouth. Remember you also need at least .002 inches of clearance in the neck or again pressures will skyrocket! If you follow this procedure you will bypass alot of grief!
Now once you have tried to do as I have described and have wrecked half of your cases, you will do as I am going to do and neck ream my chamber out to .613 tapering to .614 to avoid this nightmare.
You can generate all the pain you want with this cartridge. I doubt your reeling senses could tell the difference between the 2.8 inch case or the 3.0 inch version. Perhaps only your retinal re-attachment Surgery specialist can. Just kidding! Hope this helps.-Rob

I am going to do and neck ream my chamber out to .613 tapering to .614 to avoid this nightmare.

So basically Rob I should just tell the smith to do the above and all my worries will be bansihed

I have e-mailed him some of the stuff you have written but I am not sure he appreciates it, I think he feels by doing this I am doubting his skill. But I am only trying to make things easier for him and thus cheaper for me.

Regards PC.

P.S. my mate who is also building one thinks he will be able to handle the recoil at full power without a problem. I told him he is dreaming.

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PC- Wise decision to go the the .614 neck. I've talked to JGS and they will probably make some new reamers this way. Hopefully your gunsmith doesn't get offended, but this is no ordinary run of the mill project. Unless he's done one before, why should you be responsible for sorting out the problems at your expense? There just isn't any simple solution to building this cannon. As you have pointed out it's expensive and time consuming. Why not get it right first time.
If I can save you one hour of grief,frustration or possible dangerous problems, I'm happy to do so. Hope you got the pics and video.-Rob

I can load my 577 Tyrannosaur to 2700 f/sec but then I would not even think of using it in Africa under high temperatures - pressure is MAX.
The 577 Tyr holds considerabely more powder than the 2,85" Nyati and also more than the 3" version Nyati (case is fatter on the Tyrannosaur and 2,990" length) and therefore is MORE powerfull when loaded to the same pressures. If you load all three cartridges to the exact same pressures and everything else beeing equal, then the 577 Tyrannosaur will be the fastest because of the largest casevolume. It is as simple as that.

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UH

Ulrik Hentzer,

Do you get 2700 f/s with the woodleigh 750 grain soft point bullet...? have you done any expansion test...?

Have you tried the woodleigh 900 grain bullet....? what velocity can you get with them in your 577 Tyrannosaur...?

If you can get 2700 f/s with the Nyati 3" Version and the same velocity with the 577 Tyrannosaur. Then the Tyrannosaur isn�t more powerfull than the 3" version. Isn�t that right...?

overkill !!
750 Woodleigh will expand inside out in wet phonebooks even at a lesser velocity.
I used Barnes monolithic solids, 750 grs in the previous mentioned load.
I am 100 % certain that if I load my Tyrannosaur to the same pressure as the 585 Nyati 3" load you mention, then I would get more than 2700 f/sec ( barrellength being equal ). That means that I can probably squeeze a bit more f/sec out of my tyrannosaur - but I do not see the practical purpose. In Africa I would go for a velocity in the 2550 f/sec range ( If I had the Nyati I would only go to 2400 f/sec under hot conditions..).

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UH

Ulrik-Who built your T-REX? Specifically which action are you using?-Rob

Ulrik I was only having a guess at the power levels, could you let me know what the recoil is like with your 750 grainer at 2700, I imagine it would be great for spotlighting foxes out of a ute window

Rob I got your pics and video, excellent.

Ulrik well what velocity would you get from the 3" Nyatti??

I just want to shoot 650's at around 2400-2500 for the pigs etc, and shooting lighter bullets should reduce the recoil somewhat.

Regards PC.

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I went with 2250 fps at 750 grains in Africa and it worked just great. Frankly, I would not want much more recoil than that for hunting.

Ulrik Hentzer,

Have you tried the woodleigh 900 grain soft nose bullets...?

What velocity do you think you can get in your 577 Tyrannosur with the 900 grainer...?

I think that the 900 grain bullets is the only way to get more power on hunting because the 750 grainer will explod at velocity over 2300 f/s as you guys say.

How do you guys think that the woodleigh 900 grain soft nose bullets will expand...????

OK,

If I mail you a 900 grainer, will you promise to shoot it at 2700 fps?

Overkill- Can we video you shooting the NYATI or T-Rex with a 900 grainer? I would be willing to let you try mine. I'll get the velocity up big time for you!-Rob

Guys, guys do you know what my weight is...

145 kg........!

Rob,

What velocity do you think you can get with the 900 grainers...?

I am thinking of to build a heavy rifle in the 585 Nyati 3" or 577 Tyrannosaur. At about 8 kg, then the recoil isn�t so big.

I am going to wait for about 3-4 years then i am going to build the rifle.

OVERKILL- at 145kgs. the NYATI or T-REX will nail you big time! Big guys absorb all the recoil there is and it hurts! 8Kgs without a clam shell Muzzel break firing a 900 gr bullet at lets say 2500 fps would generate a tad little less recoil than my 18lb .50BMG light rifle shooting 850 gr bullets at 2700 fps. Without that huge clamshell hanging off that gun it is capable of breaking your colarbone or worse.
As I said before, I won't even try it.

Ulrik,

What were your 577 Tyrannosaur cost you and what action is it...?????

I have not tried 900 grs bullets.
At 2700 f/s recoil is pretty fierce.. - but not uncontrolable.
My rifle is an A-Square Hannibal model builded on the modified Ennfield action. It costed me 5000 EURO + Norwegian VAT (25 %).

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UH