1. Whats parent cases were used for the .550 and the .600 O.K.

2. Whats the case capacity for each.

3. What velocities could be expected from them using 800gr semi-jacketed soft points out of a 30" barrel?

4. Whats the T.K.O. value of the the three.

5. Which is more economical to reload?

Thanks
Larry A.

P.S. Also if any of you have pictures you can post of the three aforementioned cartridges (either individually or even better, next to eachother) I would greatly appreciate it.

The 550 mag is a 460 Weatherby case blown out nearly strait, the 600 OK is a unique case.

Not sure on case capacities, but the 600 is a much larger case.

I think the 550 could do 2000 or so with an 800 gr, the OK I believe is in the neighborhood of 2400-2500 fps.

Don't know about TKO, but either one is more then enough to dispatch the largest of game, provided you can place your shots.

The 550 would be more economical, cheaper brass, and less powder. That said, none of the over 50 cals are economical to shoot. You build and buy them because you want something big and bad, and have enough money to feed them.

The .600 OK will hold 214gr of water. The 550 is based on the 460 wby case. Both are belted cartridges with straight walls and no shoulder.
The .600OK is essentially a belted version of the .600NE designed for 56Kpsi. It has driven a 900 gr bullet to over 2400fps. -Rob

Thanks for the info guys.


An off topic question for you though Rob; Are you the creator of the .700 BMG imp?

Just curious.

Larry A.

To get the Taylor Knock Out

Bullet Wt X Bore Size X Velocity and divide by 7000

The 585 Nyati is different to the other two in that it is a rimless bottle neck. It is the 577 Nitro blown out real parallel and then renecked down to .585 and the rimmed case converted to rimless (or rebated)

The 600 OK is probably the maximum size cartridge that could be fitted to a conventional bolt action such as the CZ and being a bolt action does not have the pressure limitations imposed by a double rilfe. So it is probably the maximum power you can obtain from a conventional bolt action.

The 550 being based on the 460 Wby case taken out straight (looks like a fat version of the 458 Lott as does the 600 OK) probably represents the greatest combination of power and practicality or power and ease of making the rifle.

Mike

the 550 magnum is a 3" version of a straight 460 weatherby case... designed by Neal(RNS)

it's designed to throw a 700 grain 2300+

and it CAN!!

the 600 OK was built from the ground up on a custom case by Rob!!

designed to BE ABLE to throw a 900 2400+


the 550 Express.. again designed by Neal

460 case 2.65" (it's the baby of the lot)

designed for
700 at 2100 (that's 7000# chum)
or more specifically, a 650 at 2200... (7000 again)

With the exception of the 650, all loads are at or better than the vaulted 577 nitro, ME, SD, etc...

the 650 it .004 less Sd...

amazing, awesome, bigbores...

and, of course, these barely count as primers' for Ed's stuff.

Thanks for the plug Jeff-- The 550 mag and 600 OK are built the way big bores should be for bolt actions
and Ruger #1s, like the Lott,
Capstick, and 495 A-Sq.Only they are even better; with little extra length, at 3 inches.All of mine need lengthened actions or used single shot in regular actions for my 4 smallest cases.That is nice thing about the 550and 600, is they feed with a little work from
regular actions.Rob and Neal have done great.Ed.

quote:

---

Originally posted by hubel458:
Thanks for the plug Jeff-- The 550 mag and 600 OK are built the way big bores should be for bolt actions
and Ruger #1s, like the Lott,
Capstick, and 495 A-Sq.Only they are even better; with little extra length, at 3 inches.All of mine need lengthened actions or used single shot in regular actions for my 4 smallest cases.That is nice thing about the 550and 600, is they feed with a little work from
regular actions.Rob and Neal have done great.Ed.

---

This is true Mr Hubel but your 700 HE would be great for a scaled down Borchardt action I think you'll agree.

Also while I've got your attention Mr. Hubel could you either post here or IM the step by step process in which you make your 700 HE and roughly about how long it takes per case?


Thank
Larry A.

Thanks Mike, I have saved the formula for calculating the TKo.


Larry A.

Here is a picture of the three straight belted cases



458lott, 550mag 700gr,550mag 800gr, 600OK 900gr

RNS

I think for the most part a 700gr bullet between 2100 and 2200 fps is at a recoil level where most could shoot it and become good with it. Now I am saying most people not all so if you can handle more recoil good. Also I am not talking about firing just one shot.

RNS

458 lott TKO 72 (500gr @ 2200fps)

550 Mag TKO 118 (700gr @ 2150fps)

600 OK TKO 191 (900gr @ 2400fps)

RNS

quote:

---

Originally posted by RNS:
458 lott TKO 72 (500gr @ 2200fps)

550 Mag TKO 118 (700gr @ 2150fps)

600 OK TKO 191 (900gr @ 2400fps)

RNS

---

Hi RNS,

Where in your list can we put the .500 A2?
124.5 REL 19 2314 BARNES 700 SP
125.5 2338
126.5 2378
128.5 2409

Relod datas found on accurate reloading page.

I'm very interrested in .555 mag or .500 A2

Thanks for your input.

BER007

If equivalent loading data was used, that is equal pressure with equally suitable powders, then the 550 will always be higher than the 500.

1) It will drive the same weight bullet faster than the 500 or a heavier bullet as the same speed as the 500 drives a lighter bullet

2) Taylors KO formula is Bullet Wt X Velocity X Diameter all divided by 7000

Mike

Larry and BER, other formulas you might find interesting are Wooters lethality and Ed Matunas' optimum game weight.

Wooters is bullet Kinetic energy @100 yards X sectional density of bullet X calibre.

A figure of 350+ is supposed to be the requirement for dangerous game.

OGW is (Bullet velocity in fps)cubed X (bullet weight in grains)squared, multiplied by 1.5 x 10 raised to negative 12. (Sorry for the notation)

This figure according to Matunas gives the maximum weight animal(in pounds) a calibre can take with a softpoint. bullet.


Karl.

Here is the 500A2 and the 550 Magnum



RNS

Pic failed I think RNS. For me anyway..

Karl.

Same for me but if you right click the broken picture and copy the picture URL and paste it into the address bar you will be able to see it

Did some more shooting todat and my average velocity was 2151 FPS with a 700gr Hawk

Fired and resized case capicity was 154.8gr H20

RNS

Neal,
2151 with a 700 grain? that slaughers the 577!!! 7200 ftlbs with a .331 SD vs 7000ftlbs with a .313 sd...

what's the difference in SD? that's MORE than the difference between a 750 gr .585 vs a 535 gr .510

i'll update QL on capacity!

jeffe

Although I have hunted with the .585 Nyati and like it, and although I think the .600 OK is a great cartridge, perhaps the .550 Magnum or .550 Express is the best compromise of all.

I just did a quick calc, from a 500 A-sq, 600 gr @ 2400 fps is a TKO of 105. If you're looking for a "practical" big bore, the A-sq is hard to beat, brass is relatively inexspensive and easy to get, as well as componet bullets. Once you go beyond 50 cal, componets get expensive and hard to come by.

I feel the 550 is more practical, as I got
bullets as cheap as most 50 cal bullets, and
more companies are making them. same plentiful brass as needed to make A-Sq. Just run an
expander into a 460 case like the first ones
made that I did and sent to Neal.And it will get
600 gr bullet to same speed as A-sq with little less pressure, or a little more velocity at same pressure. Dies and reamers are easier to build as there is no shoulder and for same reason brass will last longer as there is no shoulder to work.With some of the powders I will get 20 or more reloads.......When my 550 barrel gets here we will do it first with a 550 regular chamber, and test, and develop loads in a few bullet wts and about 10 powders, many of which I don't like.It is the best thing for big
Weatherby brass to be used for.Ed.

Paul,

Where the 550 might be better than the 500 is for cast bullets and I am thinking in terms of the whole bullet grooves being surrounded by the case.

Mike

Mike,

True enough on that point. My 500 Jeffrey with it's short neck is somewhat limited to my stubby 470 gr cast bullets if I want to keep the bullet base in the neck. That said it shoots them quite well.

As a fairly straightforward way to gain 10% over a 50 cal, the 550 mag is an interesting way to go. It would certainly be a nice jump for a guy shooting a 45 cal, that doesn't want to deal with exotic brass.

Paul-- You hit the nail square as they say,IE,
big power with common brass. A simple straight
case, easy to develope loads for, and will
get way over 8000 honest ft lbs. All the picky
problems guys have had with Jeffrey, Gibbs,, Nyati etc, aren't there with the 550.And another
important thing is that guys who love Weatherby
rifles can do the 550, add a little weight, and
easily(economically is the word) have a hairy blaster.In fact about 1/2 of all big WEA should be 550 Magnums...Ed.

I agree 100%; the 550 RNS Magnum is the perfect blend of power and affordability for us working stiffs. I can buy 460Wby cylindrical for loadwork development and practice, and then stuff that same load into 550 Magnum headstamped brass for the trip to Africa next spring. Cast bullets and moulds available, sounds like a great deal for the caster/handloader/tinkerer.

regards,

Rich

TKO calculator:

http://matrix.dumpshock.com/raygun/downloads/taylor.html

I imagine putting the 550 in a CZ would require a new box and follower, and rail work, yes? It feeds from the mag lips, single stack, I presume.
Anyone worked on this?

Is my math right that a barrel will be chambered, headspaced, quarter ribbed with 3-leaf, banded/hooded bead, etc for $960?
On a CZ 550 that makes about $1700 + feeding and stock work.
Anyway, about $2k for a true monster slayer. And .1#@2350?! Zoinks!

quote:

Originally posted by Bwana-be:
I imagine putting the 550 in a CZ would require a new box and follower, and rail work, yes? It feeds from the mag lips, single stack, I presume.
Anyone worked on this?

Same box and follower, a little feed work. Jim Brockman has done a few now (mine included) and the cost is just barely more than a normal rebarrel job. But for the sake of safety, some stock reinforcement is in order. Better yet, get a new stock from Jim, AHR or McMillan. Any CZ 416 Rigby is basically a ready-to-go conversion. I would guess the Ruger RSM is another easy option but a few dollars more to start.

In spring will have 550 on with long barrel to test....Have 550 bbl on Enfield..I think
I can get near 10,000 ft lbs.

Have 585 bbl on Enfield,to be 585HE--
have 458HE that fires on Enfield.I like
Enfields for smaller bores as you see.Ed.

quote:

Originally posted by hubel458:
...I like
Enfields for smaller bores as you see.Ed.

quote:

Originally posted by hubel458:
I feel the 550 is more practical, as I got
bullets as cheap as most 50 cal bullets.....

Ed.

May I ask for some links to where you are finding .550 diameter bullets for "as cheap as most 50 cal bullets?"

Woodsracer..Got a bunch from Hawk-When RNS,
jeffe and others ordered I think a buck
each..RNS has other also making some.
And I was comparing to 50cal quality
hunting bullets no surplus.Ed.

quote:

Originally posted by hubel458:
Woodsracer..Got a bunch from Hawk-When RNS,
jeffe and others ordered I think a buck
each..RNS has other also making some.
And I was comparing to 50cal quality
hunting bullets no surplus.Ed.

OK, thanks for clarifying!