I know this probably belongs in big bores but apart from an old 2006 thread there doesnt seem to be much info about this cartridge. How well has it been adopted and any reports from the hunting field?

Scott,

If I remember correctly, it's the same as the 458 3" Stewart which was developed by Ken Stewart of Stewart Bullets is Pietersburg.

In which case, my buddy (PH) Colin Kirkham uses one to great effect and loves it to death. Cases and loaded ammo are available from Ken Stewart at least and probably from others.

Let me know if you need Ken's contact details.

Hope that helps.

The .458 Express/Stewart 3" is a better cartridge than the .458 Lott, because larger case capacity (higher velocity/lower pressure)and it fit the same actions as the .458 Lott!

Hope some maker starts to chamber the .458 Express/Stewart 3" and that Norma makes African PH ammunition and cases for it!


Shakari,
Why doesnt PMP make .458 Express/Stewart 3" ammunition and cases? African caliber for African game!

Husky,

I believe Ken has come to an arrangement with one of the local maunfacturers for them to make and load his design bullets and would guess they'll load the 458 Stewart 3" as part of that.

'Fraid I can't remember which manufacturer it is and he's away at the moment, so I can't call and ask him.

Hi Shakari,
Could it be Piet at Nobletech, Pretoria?
I have been there with Ken.

That name certainly rings a bell with me, so yes, I'd say it's more than possible!

There seems to be a slight difference between the 458 3" Stewart and the 458 Express.

Here is the link and all the work they have done ... http://www.458express.com/

Warrior

Hi Scott, maybe of some help i hope, but I remember reading a back-issue of SA Hunter/Jagter that had an article (in Afrikaans) on this cartridge, but unfortunately have no idea what issue it was. It included reloading data, most of the loads seemed like average Lott loads (all were with S335 or S321 I think).

The main point was that the Lott case is a bit short on space with S335, and S321 although you can get around 82gr in a Lott case behind a 500gr bullet, chamber pressures are rather high apparently, and similar loads in the 3 inch case make it tolerable. I don't know how many people actually have problems though in the field with the Lott and sticky bolts with heavy loads, but would be quite interesting to know. I remember reading Gregor Woods using around 80gr S321 behind a 550 Woodleigh and not complaining of high pressures! I am sure that ballistics when loaded a bit hot would be on a par with the Ackley, if not a bit better. It seems to have a fair following, and would probably be quite a bit more popular than the Ackley over in SA, although the Ackley has no flies on it.

Here is an extract of some pressure testing that was done by Prof Koos Badenhorst in his 458 Express, using a 500 gr Hornady FMJ bullet at a velocity level of 2,275 fps for both loads:

1) With 81 grains of S335 it yields a chamber pressure of 61,566 psi.
2) The magic of the 458 Express is that it has the capacity to take a duplex load of 84 grains of S335/S365, which yields a very low chamber pressure of 48,764 psi. The slower burning S365 must be near the primer and then the faster burning S335 must be added for still an uncompressed load without the use of a long-drop tube.

Most 458 Lott reloaders that wish to ring out more velocity use S321 instead of S335, but that comes at a cost of higher pressures.

1) The 458 Lott can only take 75/76 grains of S335.
2) Longer 500 gr monolithic bullets rob even more powder capacity and velocity levels drop further.
3) Most PH's use the 458 Lott between 2,100 - 2,150 fps as a safe guard against rising temperatures.

Warrior

Just to get back at the longer monolithic bullets in comparison with Hornady's FMJ bullet:

500 gr Hdy FMJ .............. 34.85 mm
475 gr PMP Solid ............ 37.01 mm
500 gr Barnes Solid ......... 39.14 mm

It is clear from the above to what extent powder capacity is eroded by choice of the bullet.

The new 450gr Barnes Banded solid comes in at 35.56 mm and is of better design - featuring more pressure grooves in which the metal can flow and a redesigned FN tip.

Warrior

I would love to see the measured pressure of the 458 Lott when people claim they can reach 2,300 fps, using a 500 gr bullet with S321. Has anybody done that yet to have the pressure tested by a lab? Just curious to know? My guess would be that they are running above 65,000 psi and that is pretty high that any slight change in one of the key parameters might just tip it over the edge to give the user a stuck case, rendering him at risk of a second follow up shot.

Let us just summarize to get a worst case scenario to see how pressure can jump:

Tighter barrels" From zero psi to 3,600 psi

Temperature increase of 36 degrees C: From zero psi to 4,960 psi

Switching from a lead-core bullet to a solid: From 3,625 psi to 6,250 psi

Seating a solid bullet to touch the lands: From zero psi to 7,200 psi

Hardening of case neck: From zero psi to 9,600 psi

Nothing wrong by keeping a 5% safety margin on max safe pressures to allow for a change in variables.

Lower pressures are just that much safer when it comes to the DG hunting, as achieved by the 404 Jeff and 416 Rigby.

Now the 458 Express with its duplex load can claim similar low pressures.

Warrior

A wee bit of wet-behind-the-ears gushing about the 3" .458. What?
The same can be done with a .458 Lott and a bullet long enough to fill the 3.85" box of a CZ or BRNO. The standard Lott throat is long and wide enough, same as the standard .458 WinMag throat.

Warrior's link was good for a chuckle:



Quote:
With his Ruger No,1 chambered in .458 Express, Dave Campbell from Chickaloon St. in Eagle River, Alaska wrote:

" ...of all the different large bore rifles I own, I have never felt the thrust and satisfaction (sic) that I do with my .458 Express. I've got a rifle and cartridge combination that I would walk straight up to the gates of hell with, shout at the devil and I know that I would come back home..."
Unquote



Was that supposed to be "trust and satisfaction" or was he just being horny?

Speaking of deep throats, does anyone have the throat specs on the .458 Express 3" or Stewart?
Maybe they need some throat Weatherbizing to handle the long bullets better?

Yada Yada Yada all the hoohaa

Get a Bloody 450 Rigby if you want the 2300/500Gr number and then you will not have any , I state again any Pressure Problems , or THE NEED FOR DUPLEX LOADS

Easy too load easy too shoot VICTORY TOO THE 450 RIGBY

oh my poor little 458WM is feeling so emasculated right now! What will I ever do?

Walter what if you already have a .458 Lott and you are battling to achieve low pressure/good velocity with Somchem powders? Continually buying Federal ammo is enough to make anyones eyes water!

quote:

The slower burning S365 must be near the primer and then the faster burning S335 must be added

It does not matter what goes where, it is a myth that it makes a difference.

quote:

Switching from a lead-core bullet to a solid: From 3,625 psi to 6,250 psi

Seating a solid bullet to touch the lands: From zero psi to 7,200 psi

These do not apply to solid copper drive band bullets.

quote:

Just to get back at the longer monolithic bullets

Interesting choice of words.

quote:

Warrior's link was good for a chuckle

Indeed, so is Warrior.

Too ream any 458 WM or Lott too 450 Rigbyis a piece of pie, Kevin Healy, Ginger Van Zyl, and a number of other in SA does it good

I just hate too see over 54000 PSI ,

In my limited brain capacity I have this Equation: Higher Pressure in any same speed/weight = higher kick back

A pair of very nice African cartridges.

quote:

quote:
Warrior:

The slower burning S365 must be near the primer and then the faster burning S335 must be added

Gerard:

It does not matter what goes where, it is a myth that it makes a difference.

Gerard you are wrong again, it does make a difference. It has been tested by the SAP ballistics department. You do not have to take it from me, as it will be a never ending saga of denial ending up in name-calling like you are known for.

For your elucidation, I suggest that you check the info out with the designer of the caliber, Prof Koos Badenhorst. I called Koos about your statement to verify it once more - it is not a myth. You can redeem your ignorance by phoning him on his cell 082-569 8660.

Then we can see who gets a chuckle.
I am already smiling.


Warrior

RIP,

I have noticed that big-bore wildcats are always marred with rivalry and jealousy. That was also so in the days of Watts and Lott. Lott was accused of copying Watts, but Lott did make a an improvement to the Watts as can be seen here as written by Cal Pappas ...

"On re-chambering, there seems to be quite a bit of confusion over the minute variation between Watts and Lott. All the modern chambering reamers make the chamber long enough to accommodate a case 2.85" long, and any difference is simply in the throat dimensions. It wasn’t always like that, and I have frequently seen rifles converted to .458 Lott in South Africa that were only made to accommodate a case 2.80" long. This is a real problem when trying to use modern A-Square Factory ammo, or even most reloads. The front of the chamber pinches the round in the area of the crimp. Chambering of the longer rounds is frequently possible but the pressures are through the roof as the crimp cannot unfold to release the bullet (a bit like firing 2 ¾" shot gun shells in an old shotgun with 2½" chambers, something has to let go sooner or later). Make sure when you order the conversion you specify that you will be using the longer cases:- I cannot emphasise this enough, just be sure, very sure. On throat dimensions, Jack Lott got it right. The longer throat lowers pressure and that is definitely required in a dangerous game rifle. Consequently, I don’t know why anyone will order a rifle chambered for the short throated Watts anymore."

The same happened again by designing another offshoot, namely the 458 Express.
It does offer some benefits.
Benefits are always in the eye of the beholder.

Warrior

Even Holland & Holland felt the need to introduce yet another big-bore DG cartridge, namely the all new .465 belted magnum cartridge. The .465 H&H Magnum is a cartridge with very similar performance to the .450 Watts Magnum, .458 Ackley or .458 Lott, but which operates at lower pressure and is designed specifically for the extreme heat of the sub-Saharan African hunting environment. The .465 uses the same .468", 480 grain bullets as Holland's successful .465 Nitro Express elephant rifle cartridge for double rifles. The new .465 H&H case is based on the oversize .378 Weatherby case. It uses a .603" diameter rim and belt. Overall case length is 2.894" and the standard cartridge overall length is 3.50". Factory loaded bullets are to be supplied by Woodleigh of Australia. These will be the same 480 grain solid The sectional density of these bullets is .318, and the ballistic coefficient is .407-.410. Holland & Holland factory load ballistics call for a 480 grain bullet at a muzzle velocity of 2,375 fps and ME of 6013 ft. lbs. At 100 yards the figures are 2,143 fps and 4905 ft. lbs. These ballistics pertain to a rifle with a 24" barrel.

Warrior

I think that there is also a 2.85 inch version of the Lott, which would make a slight difference. As RIP says, if the magazine and throat allows it, you should be able to tweak the COL a bit and squeeze a bit more out of it, although crimping may be a problem. As a matter of interest, how does S341 perform in the Lott accuracy/velocity/pressure wise with 500gr bullets? Pressures should be a bit lower than using S321, but you should be able to get about the same amount in the case as S321?

Well, here is another Express; the 550 Express. I guess it is for those that see the the 458 family as a varmint round.

The 550 Express was designed to be the most powerful round one could legitimately fit into a sporting/hunting Mauser.
It shoots 700grain bullets at 2,124 fps !!!

Here is the link ... http://www.weaponsmith.com/550-exp.html

Here is another interesting article ... "Mini Compendium of Big Bore Cartridges
by Daniel McCarthy .... http://www.470mbogo.com/BigBoreCompendium/


Warrior

quote:

Too ream any 458 WM or Lott too 450 Rigbyis a piece of pie, Kevin Healy, Ginger Van Zyl, and a number of other in SA does it good

My knowledge is admmitedly limited but dont you have to alter the bolt face and make far more complex changes than those undertaken when a .458 WM becomes a lott/watts/3" express?

Cartridge --- Dia --- Weight --- Velocity ---- Mo ----- Xsa ----- Mo/Xsa
338 Win Mag - .338 -- 250 gr -- 2,600 fps -- 92.9 -- .11424 -- 812.8
9,3 x 62 mm - .366 -- 286 gr -- 2,300 fps -- 94.0 -- .13396 -- 701.5
375 H&H ----- .375 -- 300 gr -- 2,530 fps --108.4 -- .14063 -- 771.0
416 Rigby --- .416 -- 400 gr -- 2,415 fps --138.0 -- .17306 -- 797.4
404 Jeffery - .423 -- 400 gr -- 2,250 fps --128.6 -- .17893 -- 718.6
458 Win ----- .458 -- 475 gr -- 2,000 fps --135.7 -- .20976 -- 647.0
458 Lott ---- .458 -- 450 gr -- 2,325 fps --149.5 -- .20976 -- 712.5
458 Lott ---- .458 -- 475 gr -- 2,300 fps --156.1 -- .20976 -- 744.0
458 Express - .458 -- 500 gr -- 2,275 fps --162.5 -- .20976 -- 774.7
500 NE ------ .510 -- 570 gr -- 2,150 fps --175.1 -- .26010 -- 673.1
500 Jeffery - .510 -- 570 gr -- 2,300 fps --187.3 -- .26010 -- 720.1
500 Gibbs --- .505 -- 600 gr -- 2,325 fps --199.3 -- .25503 -- 781.4

Warrior