Enabled by boom stick, good Lord deliver us, as the nightjar would say:







It can easily be a 7-shooter in a CZ 550 Magnum.

Take your pick for the poor man's DGR with bona fides,
either a 7-shooter .458 Lott or the more gentlemanly 7-shooter "400 Karamojo."

I bet W.D.M. "Karamojo" Bell would prefer the 400 Karamojo.











Here is a 4-shooter load (3 + 1) of .423/375H&H as might be used in the standard Winchester M70 Classic box,
but of course you can do a 6 + 1 seven-shooter with it too, in a CZ 550 Magnum:



And last but not least, the 5-shooter (4 + 1) of the Pre-64 Winchester M70 which can be used with any of the
otherwise unadulterated .375 H&H neck-ups, all slick as greased owl poop for feeding, even this .395/375 H&H:



The .458 Lott, due to the loss of body taper, is not quite as slick.
The .423/375 H&H is the maximum caliber, perfectly spot on, for maintenance of body taper.

Riflecrank Incurable Permanente

By Jove, where is my monocle!!!
Do I see before me the ultimate gentlemans round? If "Karamojo" Bell had designed a DG cartridge this would be that raskle of a dickens. Thanks RIP for making the Wildcat Cartridge centerfold porn can you tell us what the actual neck diameter and neck shoulder junction is? Methinks it could do 400@ 2,300 fps or a more gentle 2,150 without issue and as slick as butter on Teflon.

The .410/375 H&H Karamojo necks made with Winchester (W-W Super) .375 H&H brass measure no bigger than .434" +/- .001" diameter.

So it seems the .436" brass maximum spec for neck-1 and neck-2 might be OK.

Any reamer cut for it would be about +.004" over .436", or .440" at the neck-2.

Or go tighter to a minimum reamer neck-2 of .438".

Reamer neck-1 might be same, or add another .001".
Reamer neck-1 = .439" diameter minimum at shoulder.
Reamer neck-2 = .438" diameter minimum at case mouth.

Depends on which way the wind blows, after trying some other brass makes, like Hornady basic cylindrical H&H, etc.

Yep, your velocity estimates are spot on.

If the 400 Whelen can do 2200 fps with 400-grainers, and has a case capacity of about 77 grains water,
then the "400 Karamojo" with case capacity of about 95 grains water (23% larger) should easily do 2300 to 2325 fps with 400-grainers.

The 400 Karamojo cartridge has a smaller shoulder diameter (.4478" at 2.4122" from breech)
than the 400 Whelen (.4550" at 2.000" from breech).

To be continued.
I just got home from photo-bombing a wedding reception photo session, 3-hour drive from here. Exhausted ...

Riflecrank Incurable Permanente

I read that a ghost shoulder aides in accuracy. Can anyone elaborate how this is done?

A ghost shoulder is just a segment of parallel-sided neck near the end of the cartridge.
Even the .458 Lott loads pictured above have about a caliber length of neck gripping the bullet that is parallel-sided and same diameter,
no more difference than any increasing thickness of brass going baseward.
No ghost shoulder designed into the chamber, but it is there in the ammo.
Hopefully aligned with bore!
Careful sizing, +/- expander balls and belling plugs not over-applied, plus concentric seating takes care of it.

I think a ghost shoulder is much ado about terminology.
Sounds neat doesn't it?

I have another sixshooter (5 + 1), fully loaded with this:








A 400 Whelen in a Winchester M70 Featherweight 270 WCF action,
opened up to +3.6" box length with a Duane Wiebe XRM box and thinnest follower and spring I could find.
It has been seen here before, but I just today finally put that XRM box in it,
used files and chisels on the inside of the tupperware stock:





I tried a Sunnyhill-McMillan-Winchester M70 combo dropbox, but could get only six down in the box, and really tight it was.
Will not make a 7-shooter.
So above sixshooter is it for the Whelen.
Whether .411-caliber as is, or maybe a .410/400 Whelen.
Afterall, the original 400 Whelen of 1923 was a .409-caliber,
so .410-caliber would be a step in the right direction.

Above rifle could now have boltface opened up to .375 H&H, since it has the box length for it, another 400 Karamojo candidate.
Might be a five-shooter (4 + 1) like the Pre-64 M70.

For the gentleman's DGR, a 400 Karamojo:
CZ 550 Magnum seven-shooter about 9 pounds bare and empty,
or
Winchester five-shooter under 8 pounds bare and empty?
Or a 400 Whelen Winchester sixshooter?

Riflecrank Incurable Permanente

With such gentlemanly recoil the lively and nimble M70 could be quite the platform for this dandy round. I think an 8lb rifle would be a delight to carry and shoot.

So here is the jumbo question. Should the chamber reamer continue the taper without a shoulder and only a sub caliber neck tension area that is parallel sided and the reloading dies give it a full caliber neck tension area that it has now with the micro shoulder? I like the clean look of the the 404-375 and 458 Lott. It is merely cosmetic I know. The 404-375 has that cool body taper to neck without the shoulder and the 400 Karamojo can have that too but I would prefer it to have a full caliber neck tension area that could be had with the right dies. Would that be too much brass expansion that could cause neck splits? I think the KISS principle might win. Learn to love your wrinkles. I see this as the more practical and longer 40 BSA for the common folk with a flair for the modern retro.

Either or, it is a righteous cart on the path of the enlightened before it taking a trail that is less travelled. Blessed be all that behold and can comprehend the wisdom of the Karamojo

With out much evidence--I would stay with the 404-375

D,Arcy sure likes it.

I am probably the biggest fan of the 404-375 as you can tell by a quick search or the link in my signature line but this is a new beast and kissing cousin with a whole slew of bullets to chose from. I like the availability of cheap bullets for plinking and hunting with the option of premium bullets at relatively light recoil. Don't get me wrong though. I love the big boomers too.

Best I can tell, from previous research, while looking for the elusive aboriginal .395-caliber BPE bullet of the 1870's,
the ".40 B.S.A. Magnum" was a true .400-caliber, with .400" diameter bullet.
250-grain copper-pointed bullet with 69 grains of cordite was the standard load (shown by boom stick's photo),
and early production loads had no headstamp and a heavier roundnose bullet, according to Hoyem.
Hoyem (not always right) says it was a Birmingham Small Arms development for the sporting version of the Pattern 14 Enfield rifle in 1921.
It never went into full production.
Quite the collector's item now.

The .410/.375 H&H Unadulterated has a .416"-long neck if the brass is made 2.850" long, like the .375 H&H max length brass.

Turning that micro-shoulder into a ghost shoulder (pattern a reamer after the 470 Capstick reamer) would be a nice cosmetic touch,
making it even closer in performance to the 3.6" 400 Whelen.
It's making me want a .410/400 Whelen even more, for a .001" better shoulder!
Talk about picking the fly poop out of the pepper ...
But that is what wildcatters do.

Riflecrank Incurable Permanente

I think the K.I.S.S. rule and the path of least resistance wins. I think the practicality and simplicity of this cart is part of the beauty of it.

boom stick,

You'll have build that one yourself, the only "ghost shoulder I am building is on the .500 Buhmiller.
And I am stuck on the .410/404 Jeffery Justified: versatile as the 400 Karamojo,
even if I have to give up a 6 + 1 seven-shooter
for a 5 + 1 sixshooter.



Riflecrank Incurable Permanente

I think the best thing is to just stick a .410" pilot reamer in an existing 375 and keep it simple.

A big thank you to RIP for sending me a couple dummy rounds. I think RIP works for Fort Knox because that was the best wrapped and most secure package I ever received I like the 400 Karamojo verrrry much!

Rip.

Why all the decimal places?

The neck to shoulder joint is at 2.4342", why not just make it 2.45" and leave a .40" neck length?

So comparing this to the 400 H&H what are the advantages / disadvantages?

quote:

Originally posted by chuck375:
So comparing this to the 400 H&H what are the advantages / disadvantages?

It doesn't have a belt, it requires custom reamer and loading die design and manufacture, there is no factory ammunition for it, it..it..it...... did I mention it doesn't have a belt?

So the "new" 10,3x68 RWS would be 4mm shorter. but basically the same-ish.

No that would be like the improved version of the .400 H&H necked down 0.14mm and shortened, sort of like a .405-400 H&H AI short. If you ignore the 10.3mm bullets instead of 10.4mm I guess you could call the 10.3x68 RWS a .400 H&H Short Improved.

Oh, gotcha!

I missed the measurements.

quote:

Originally posted by Fjold:
Rip.

Why all the decimal places?

The neck to shoulder joint is at 2.4342", why not just make it 2.45" and leave a .40" neck length?

That is an artifact of keeping the cartridge identical to the .375 H&H up to the 15-degree shoulder, and same Brass Overall Length: 2.850".

The rest is 'puter-exact calculation, completed by guesstimating a Neck-1 and a Neck-2, and later refined with sample brass in hand.

So, a neck-1 was chosen that was .001" smaller (to allow for case neck wall thinning on necking up),
.001" smaller than just adding the bullet diameter difference to the neck-1 of the .375 H&H.

Bullet diameter difference.
.410" - .375" = .035"

Neck-1 of .375 H&H = .402".
That is a max brass spec, which is smaller in actual, real-world-manufactured brass, as it should be.

Add .402" + .035" = .437".

But brass neck walls will thin a little on necking up.
Therefore: Choose .436" for the max brass spec of the 400 Karamojo.

Ask boom stick for any further refinements.

There is more than one way to skin a wildcat!

Riflecrank Incurable Permanente

Something I was trying to see was the points of contact between carts for friction and feeding and there is pretty much a straight line from the belt to the shoulder to the case mouth and barely clearing the bullet so this in theory should be a slick feeder just as much as the original 375 HH

Sooooooooo thinking about this 400-375HH some more. If you kept the same angle of body taper of the 375 HH you would end up with the same diameter as the neck diameter of a 411 cartridge. If you just had a chamber dimension a few thousandths over the cartridge dimensions you would basically have all taper and no parallel sided neck. What real world issues would this cause? Should there be a small unfired cartridge parallel sided neck area but straight taper on the chamber with no neck? Thoughts?

Anyone have any opinions on the above question? The “neck” portion would be tiny but would it have any serious issues?

I don't have an opinion on your question, but I do have this cartridge and rifle; it's a Zastava LH action in 400H&H built by Weaver Rifles, donor rifle supplied by our AR friend Bluefish.

It is a shooter, and favors the 370g CEB's and a couple different weight North Forks. I'm still a bit irritated that I can't buy .411 TSX's yet.

I have previously regretted my decision to pursue the unsupported H&H cartridge, but it's worked out now so I'm a little satisfied.

I've resized WW Super brass and bought 60 pcs of Roebeson Brass before they went Tango Uniform.

Yeah I guess it may as well be a wildcat but wild is where the fun is
Commercial offerings are like Wednesday night copulation but a wildcat is a Friday night 24 hour rodeo.

quote:

Originally posted by Scott King:
I don't have an opinion on your question, but I do have this cartridge and rifle; it's a Zastava LH action in 400H&H built by Weaver Rifles, donor rifle supplied by our AR friend Bluefish.

It is a shooter, and favors the 370g CEB's and a couple different weight North Forks. I'm still a bit irritated that I can't buy .411 TSX's yet.

I have previously regretted my decision to pursue the unsupported H&H cartridge, but it's worked out now so I'm a little satisfied.

I've resized WW Super brass and bought 60 pcs of Roebeson Brass before they went Tango Uniform.

Scott
Got some pics of that 400?

The Lott seems all taper but will that work with a bullet .047” smaller?!? V

https://www.africahunting.com/...458-lott-png.341130/

Talking to myself… if my geometry is right, with the current taper of the 375HH, that would give about 1/4” of parallel sided neck before gently tapering open going towards the base. That should be enough neck/bullet contact area with a crimp. This would be a fine looking cartridge with no shoulder. I need to get one.

I saw the header, 400/375 and thought I would see load data...... didnt look at the Karamojo.
I have a 400/375 belted nitro I built for fun. Think of a 375/240 weatherby. Not the same thing!