Since I already have 458 Lott I am thinking of have my 458 Mag rechambered to 450 Rigby. Any one of you big bore guys have done it? Whoo would you recommend for the job?

That is a fine idea if it is a CZ 550 Magnum, a BRNO ZKK 602, or other true Magnum action.

I have converted two CZ 550 Magnums to .458 Lapua Tembo, one by rebarreling a .416 Rigby, and one by simply rechambering the .458 WinMag factory barrel and tweeking and polishing the rails and ramp.

This is a snap.

Of course the .458 Lapua Tembo is a slicker cartridge than the .450 Rigby of circa 1995 upstart, and will do 2500 fps with 500 grainers, and any more than that is silly.

I prefer the .450 Dakota in a Prechtl Magnum Mauser 98 from SIGARMS, over any .450 Rigby.

The .450 Dakota has a much richer history, is older, and more nostalgic than the .450 Rigby.

.450 Dakota brass is readily available.

But the .458 Lapua Tembo is the best .458 of all, in the whole wide world.

An engraving pen is all I need to turn .338 Lapua Magnum brass into .458/.338 Lapua Magnum brass.

.338 Lapua Magnum brass is that GOOD: It is worth the trouble.

Thanks for imput RIP,
See what have you done? I had such a simple problem. Now you completelly turned my head by giving me too much information. You guys just know way too much. It is CZ 550 Safari I am tallking about. I looked at both Lapua and Dakota after your suggestion. How do you make Tembo brass? Fireforming it? Where can I get dies? I am fairly good with hands but I am not sure if I can handle rechambering withour lathe. I would hate to butcher it. How much work if any is required for bolt face? Appreciate your advice.

Ron, what is the difference between the 450 Rigby & 450 Dakota?

To RIP,

Please give all the case measurements for this .458 LAPUA TEMBO, thank you.

quote:

Originally posted by fla3006:
Ron, what is the difference between the 450 Rigby & 450 Dakota?

Hi Forrest,
I own a .450 Dakota Mauser, so have the headstamped brass and dies for that. The ".450 Rigby Rimless" specs I get from the book, to compare the two.

There is really no significant difference. Both can be formed from .416 Rigby brass.
Referring to Ken Howell's book (Designing and Forming Custom Cartridges):

.450 Dakota cartridge/brass specs:
head and rim diameter: 0.582" (Dakota Drawing)
length: 2.900"
base to shoulder: 2.3240"
base to neck: 2.4000"
shoulder diameter: 0.5600"
shoulder angle: 26 degrees
solid brass weight: 1502 grains
water displacement (exterior): 176 grains

.450 Rigby Rimless:
rim diameter: 0.5902" (CIP maximums)
head diameter: 0.5772" (Typo???)(If not, it ain't rimless!)
length: 2.8937"
base to shoulder: 2.3425"
base to neck: 2.4016"
shoulder diameter: 0.5709"
shoulder angle: 40 degrees
solid brass weight: 1523 grains
water displacement (exterior): 179 grains

rim thickness for both is 0.0650"

The .450 Dakota is a way better design, IMHO.

quote:

Originally posted by BigFiveJack:
To RIP,

Please give all the case measurements for this .458 LAPUA TEMBO, thank you.

Jack:

If the .338 Lapua is also known as the 8.6x70mm,
then the .458 Lapua Long Tembo is the 11.6x69mm.

It is the .338 Lapua Magnum necked up to .458 with max brass length of 2.700", trim to 2.690". The .338 Lapua max length is 2.7244" from Lapua Drawing.

.458/.338 Lapua Magnum
.458 Tembo
.458 Lapua Tembo Long Tusk
Or whatever one wants to call this most excellent of .458's:


rim diameter: 0.5878"
head diameter: 0.5870"
base to shoulder: 2.1614"
base to neck: 2.2354"
shoulder diameter: 0.5450"
shoulder angle: 20 degrees
neck length: 0.4646"
neck1 (diameter): 0.4850"
neck2 (case mouth): 0.4840"
Shoulder diameter - neck1 = 0.0600"

estimated brass exterior water displacement: 165 grains
estimated internal water capacity: 125 grains

throat:
freebore diameter: 0.4590"
parallel-sided freebore length: 0.4600"
leade: 1.5 degrees

Of course the Long Tusk seating of bullets in the Tembo makes the effective internal case capacity much closer to the .450 Dakota or .450 Rigby. Those latter two waste a lot of case capacity with bullets buried deep in the case.

Yep, the .458 Lapua Long Tusk Tembo is the best .458 in the world.

HA!/DOA is embarking on a joint venture with Barnes Bullets. We'll be loading TSX "softs" in all our ammo.

Loaded cartridge overall Length: 3.800"

btt

I second the Dakota design specs. But I also always thought it held more water.
From what I hear, the Rigby is a necked up 338 Pegasus (A-Square) so it might actually be onlt.580" at the base.
The Dakota has a bit more taper and a bit longer neck, but I'm not sureI would turn down a Rigby on the basis of that.
And anyway, either makes a great 470 Mbogo! ;-)

quote:

Originally posted by RIP:
btt

They are all based on the .416 Rigby case. Any dimensional differences in the head and rim diameters is just quibbling over max and min and quality control.

One thing is certain, quality control is best on these:

.338 Lapua Magnum
.458 Tembo Long Tusk

quote:

Originally posted by Bwana-be:
I second the Dakota design specs. But I also always thought it held more water.
From what I hear, the Rigby is a necked up 338 Pegasus (A-Square) so it might actually be onlt.580" at the base.
The Dakota has a bit more taper and a bit longer neck, but I'm not sureI would turn down a Rigby on the basis of that.
And anyway, either makes a great 470 Mbogo! ;-)

New to me. That is a strange head diameter for the .450 Rigby which is supposed to be a "Rigby" afterall, what?

Well, call it hearsay. But I heard A. A. designed the round.

No, I seriously doubt that because when it was first announced, I wrote Alphin suggesting that he chamber for it. The answer was a polite but firm "not interested". Paul Roberts, who owned Rigby at the time, designed it. It didn't take much designing as it's simply a necking up of the .416. I don't think that there's a gnat's eyelash worth of difference between the Rigby, which is available from Honebar's and a few other brass manufacturers and the Dakota which is propriatory. The loading data is the same as the .450 WBY if you want to go hot or you can ease back to around 2250-2300 and get all the stopping power you ever need. That other thingamajig is a pure wildcat and has the wildcat's fascination for wildcatters. No animal will ever know the diffence if hit with any of them.

quote:

Originally posted by Oldsarge:
No, I seriously doubt that because when it was first announced, I wrote Alphin suggesting that he chamber for it. The answer was a polite but firm "not interested". Paul Roberts, who owned Rigby at the time, designed it. It didn't take much designing as it's simply a necking up of the .416. I don't think that there's a gnat's eyelash worth of difference between the Rigby, which is available from Honebar's and a few other brass manufacturers and the Dakota which is propriatory. The loading data is the same as the .450 WBY if you want to go hot or you can ease back to around 2250-2300 and get all the stopping power you ever need. That other thingamajig is a pure wildcat and has the wildcat's fascination for wildcatters. No animal will ever know the diffence if hit with any of them.

Spot on Sarge.

Note that I have added a few more dimensions to the .458 Tembo Thingamajig, above, and it is so beautifully perfect that I will repeat it for BigFiveJack below.

Ain't the .458 Lapua Thingamajig a sweetie?

quote:

Originally posted by RIP:

Jack:

If the .338 Lapua is also known as the 8.6x70mm,
then the .458 Lapua Long Tembo is the 11.6x69mm.

It is the .338 Lapua Magnum necked up to .458 with max brass length of 2.700", trim to 2.690". The .338 Lapua max length is 2.7244" from Lapua Drawing.

.458/.338 Lapua Magnum
.458 Tembo
.458 Lapua Tembo Long Tusk
Or whatever one wants to call this most excellent of .458's:


rim diameter: 0.5878"
head diameter: 0.5870"
base to shoulder: 2.1614"
base to neck: 2.2354"
shoulder diameter: 0.5450"
shoulder angle: 20 degrees
neck length: 0.4646"
neck1 (diameter): 0.4850"
neck2 (case mouth): 0.4840"
Shoulder diameter - neck1 = 0.0600"

estimated brass exterior water displacement: 165 grains
estimated internal water capacity: 125 grains

throat:
freebore diameter: 0.4590"
parallel-sided freebore length: 0.4600"
leade: 1.5 degrees

Of course the Long Tusk seating of bullets in the Tembo makes the effective internal case capacity much closer to the .450 Dakota or .450 Rigby. Those latter two waste a lot of case capacity with bullets buried deep in the case.

Yep, the .458 Lapua Long Tusk Tembo is the best .458 in the world.

HA!/DOA is embarking on a joint venture with Barnes Bullets. We'll be loading TSX "softs" in all our ammo.

Loaded cartridge overall Length: 3.800"

Thank You RIP!

to answer your question..

it would work on the enfield, the cz602/550, and perhaps anything 460 weatherby

jeffe

Rip: do you have pictures of a 416 Laupa?

I thought the 416 rigby was better then the 416 Rem because it has more "boiler" room, wich means lower pressure, and therefor better in hotter climates. How does a 416 Laupa compare?

Im wondering, is the line up of cartrigdes you post pictures of, all based on the 338 laupa case?

Nortman,
Thanks for asking, but I am leaving the .416 Lapua alone. The .427 Lapua Kifaru Horn (.423 caliber) is close enough.

Six of the HA!/DOA cartridges are Lapua based. The .470 Mbogo is .416 Rigby basic, and the .509 Barnes Buffalo is .505 Gibbs based.

Allow me to refine the listing one more time, please:

Left to right above:

.457 Lapua Boom Stick
.307 Lapua Chui
.337 Lapua Simba
.377 Lapua Nyati
.427 Lapua Kifaru
.457 Lapua Tembo
.470 Mbogo
.510 Tatanka

BTW, the ".XX7 Lapua ..." cartridge designation format henceforth replaces the "Tusk" crap. This designation using the "7's" as terminal digit indicates the "long nose" bullet seating, except for the Boom Stick (the sole short-necked and short-nosed Lapua Cartridge), always an exception to the rule, there are no absolutes, it depends, etc.: Viking Law.

HA!/DOA recognizes that there is nothing new in wildcatting. We have collected an assemblage of excellent cartridges to serve any big game use for a magnum bolt action.

The .457 Boom Stick is meant for use in a standard Mauser length action. Though the short neck of the Boom Stick may be criticized, it is no worse than that of a .500 Jeffery. It is also not rebated and is no longer than 3.340" COL, so is a lot easier in a .30-06 length action.

Actually, my first thoughts of wildcatting the .338 Lapua Magnum started (1997) with the idea of necking it up to .416 to utilize the stout Lapua brass and bring it back to the bullet caliber of the parent cartridge (.416 Rigby).

That fell by the wayside but we might be persuaded to add a bit of redundancy and a ninth cartridge to the lineup. Lessee ...

Dakota Arms, Inc. has one .416 and two .404's, only one of their eight is .338 Lapua based.

HA!/DOA has one .404 and two .458's, and a total of six cartridges that are .338 Lapua based.

They have a 7mm and a .416 (we don't), versus the .470 and .510 offered by HA!/DOA. Yep, we bad.

Do we really need a ninth cartridge? Another .416? .007" smaller than .423?

Nortman,
If you or anyone else has any specific questions about "performance" of these wildcats, please ask them in public.

I think that more benefit can come from public discussion.

I have a thick skin, and enjoy a contest now and then.

quote:

Originally posted by RIP:

quote:

Originally posted by fla3006:
Ron, what is the difference between the 450 Rigby & 450 Dakota?

Hi Forrest,
I own a .450 Dakota Mauser, so have the headstamped brass and dies for that. The ".450 Rigby Rimless" specs I get from the book, to compare the two.

There is really no significant difference. Both can be formed from .416 Rigby brass.
Referring to Ken Howell's book (Designing and Forming Custom Cartridges):

.450 Dakota cartridge/brass specs:
head and rim diameter: 0.582" (Dakota Drawing)
length: 2.900"
base to shoulder: 2.3240"
base to neck: 2.4000"
shoulder diameter: 0.5600"
shoulder angle: 26 degrees
solid brass weight: 1502 grains
water displacement (exterior): 176 grains

.450 Rigby Rimless:
rim diameter: 0.5902" (CIP maximums)
head diameter: 0.5772" (Typo???)(If not, it ain't rimless!)
length: 2.8937"
base to shoulder: 2.3425"
base to neck: 2.4016"
shoulder diameter: 0.5709"
shoulder angle: 40 degrees
solid brass weight: 1523 grains
water displacement (exterior): 179 grains

rim thickness for both is 0.0650"

The .450 Dakota is a way better design, IMHO.

Why do you think the Dakota design is "way better"?

Dumb question. Just bought a .458 Lott as a backup for my .470. (I know, the Lott will outperform the .470, but I like doubles. Humor me.) Then I see a nice .450 Rigby for sale on the AR classifieds at a good price. Buyer's remorse. (It's a really pretty Mauser -- Heym). My old books don't show ballistics on a .450 Rigby. What can ya'll knowledgable people tell me about it? How does it compare to the Lott?

All I really care about is velocity as the bullets are going to be the same. Can't see that there would be any difference Nyati or Tembo would notice. But I'm open to others' thoughts.

quote:

My old books don't show ballistics on a .450 Rigby. What can ya'll knowledgable people tell me about it? How does it compare to the Lott?

From Kynamco.

Thanks Charles. Impressive.

quote:

Originally posted by AfricanHunter:

quote:

Originally posted by RIP:

quote:

Originally posted by fla3006:
Ron, what is the difference between the 450 Rigby & 450 Dakota?

Hi Forrest,
I own a .450 Dakota Mauser, so have the headstamped brass and dies for that. The ".450 Rigby Rimless" specs I get from the book, to compare the two.

There is really no significant difference. Both can be formed from .416 Rigby brass.
Referring to Ken Howell's book (Designing and Forming Custom Cartridges):

.450 Dakota cartridge/brass specs:
head and rim diameter: 0.582" (Dakota Drawing)
length: 2.900"
base to shoulder: 2.3240"
base to neck: 2.4000"
shoulder diameter: 0.5600"
shoulder angle: 26 degrees
solid brass weight: 1502 grains
water displacement (exterior): 176 grains

.450 Rigby Rimless:
rim diameter: 0.5902" (CIP maximums)
head diameter: 0.5772" (Typo???)(If not, it ain't rimless!)
length: 2.8937"
base to shoulder: 2.3425"
base to neck: 2.4016"
shoulder diameter: 0.5709"
shoulder angle: 40 degrees
solid brass weight: 1523 grains
water displacement (exterior): 179 grains

rim thickness for both is 0.0650"

The .450 Dakota is a way better design, IMHO.

Why do you think the Dakota design is "way better"?

I used to get excited about picking the fly poop out of this pepper.
Not anymore.
Please feel free to think whatever you like about this topic and don't mind me.
Time to give someone else a chance at this topic. I am totally bored with it.

Without reading all the posts I would suggest that whatever action you have it would be much easier and far more practical to rechamber it to a 458 Lott...That is a hard caliber to beat and about at the recoil tolerance of sane men.