458 Win Mag vs 458 Lott....The facts

[Red Leg]

In TX or AZ you are not hunting animals that might kill you if you gun locks up from to much pressure. And not all powders are temp insensitive.

I am not worried about it in Africa either with modern ammunition.

 

[hoytcanon]

There still many popular powders that can change pressure significantly over broad ranges of temperature. In Canada, I am often testing loads in minus 20-30 temps... I always check them on site for any hunt where there is a considerable temperature change.

 

[TOBY458]

I think the elephant in the room, in regards to all of these pictures posted of bullets being seated way out, is the fact that I would never take this ammo on an actual DG hunt. A bullet seated so shallow in the case seems to be a disaster waiting to happen.
I have seated some bullets out a bit in my 458 Win Mag, but nothing as extreme as some of the pictures above. IMO, exceeding 458 Lott COL isn’t needed for hunting. But I suppose it’s ok for range work, where you’re just trying to get the most velocity possible.

 

[WAB]

Glad to see WAB is enjoying this.
I am too.

I find it quite amusing. Bottom line, where I hunt you’d be crazy to take a .458 WM. If something happens to your ammo you are
Going to have a heck of a time finding WM ammo. If you do find it, you’re shooting a 500 gr bullet at 2,100 if I’m generous. However, every camp has Lott ammo.

As stated previously, I am a very serious reloader. However, IMO, reloading for this class of cartridge is pointless. Buy a Lott, shoot factory ammo at 2,300 fps, and knock the crap out of buffalo and elephant. All you are introducing is more risk, more work, and zero benefit. No matter what you do to your WM it is not going to outperform my Lott where it counts, in the bush up close and personal with a big ugly.

 

[CoElkHunter]

I think the elephant in the room, in regards to all of these pictures posted of bullets being seated way out, is the fact that I would never take this ammo on an actual DG hunt. A bullet seated so shallow in the case seems to be a disaster waiting to happen.
I have seated some bullets out a bit in my 458 Win Mag, but nothing as extreme as some of the pictures above. IMO, exceeding 458 Lott COL isn’t needed for hunting. But I suppose it’s ok for range work, where you’re just trying to get the most velocity possible.

+1. I've never hunted DG, but if/when I do I'm sticking with factory Lott or .416 Rigby ammo. I've only reloaded for my .458WM and .416 Taylor so far in big bores and I personally don't feel comfortable bringing my reloads on DG hunt. I definitely wouldn't hunt DG with reloads with extended COAL. Murphy tends to follow me around a lot. LOL

 

[Frederik]

BTW Saswart, I added 0.5gr N540 extra powder to my Lott load and with the heat of this Saturday's shoot it produced 2319fps over the Labradar. Overall Cartridge length is 92.6mm or 3.65" rounded off

Reason being for adding extra powder now my 500gr SBC softs and the Impala brass solids print 0.5" apart at 30 meters. The SBC soft bullet runing at 2240fps and now the solid at basically 2300fps if you take the high temps of Saturday out of the parameter.

I am very pleased with my Lott and it does what it was intended to do so on DG and is fun to use on plainsgame. As long as you restrict yourself to 150 meters max range on larger game.

 

[CoElkHunter]

View attachment 649774

BTW Saswart, I added 0.5gr N540 extra powder to my Lott load and with the heat of this Saturday's shoot it produced 2319fps over the Labradar. Overall Cartridge length is 92.6mm or 3.65" rounded off

Reason being for adding extra powder now my 500gr SBC softs and the Impala brass solids print 0.5" apart at 30 meters. The SBC soft bullet runing at 2240fps and now the solid at basically 2300fps if you take the high temps of Saturday out of the parameter.

I am very pleased with my Lott and it does what it was intended to do so on DG and is fun to use on plainsgame. As long as you restrict yourself to 150 meters max range on larger game.

Your photo shows cartridges with three different case lengths. Is this a quiz? LOL

 

[Grumpy gumpy]

Your photo shows cartridges with three different case lengths. Is this a quiz? LOL

As mentioned elsewhere 458 express, 458 Lott, 458windbag
Gumpy

 

[CoElkHunter]

As mentioned elsewhere 458 express, 458 Lott, 458windbag
Gumpy

Thanks! I didn’t see the description included with the photo. That express cartridge must really rock and roll compared to the Lott?

 

[Bandera]

Does a critter know if it got hit a 450 grain bullet going 2200 fps or one going 2350fps?
With well placed shot… nope dead critter.
When you screw up the shot then you might very well be screwed up. No matter how fast that bullet was going.

But I will say that it does make for some interesting reading.

 

[IvW]

Does a critter know if it got hit a 450 grain bullet going 2200 fps or one going 2350fps?
With well placed shot… nope dead critter.
When you screw up the shot then you might very well be screwed up. No matter how fast that bullet was going.

But I will say that it does make for some interesting reading.

What about 500gr or even 550gr at 2300fps vs 450gr at 2200fps? Assuming of course the same bullet design abd caliber.....

 

[ldmay375]

I think the elephant in the room, in regards to all of these pictures posted of bullets being seated way out, is the fact that I would never take this ammo on an actual DG hunt. A bullet seated so shallow in the case seems to be a disaster waiting to happen.
I have seated some bullets out a bit in my 458 Win Mag, but nothing as extreme as some of the pictures above. IMO, exceeding 458 Lott COL isn’t needed for hunting. But I suppose it’s ok for range work, where you’re just trying to get the most velocity possible.

The ones I posted are only to show the throat differences. Dummy rounds to check individual rifle throats.

There are significant differences in individual factory 458 Winchester throats, and factory individual 458 Lott throats. None of those are the same. Which of course influences individual rifle velocities and psi.

Hell, certain bullets will not even be in the brass to reach the lands of certain rifles.

 

[Frederik]

Thanks! I didn’t see the description included with the photo. That express cartridge must really rock and roll compared to the Lott?

Not really the express was built as a result of lack of powders available in South Africa and the extra space allowed for slower burning powder with less pressure which resulted in less recoil with same speed.

 

[CBH Australia]

As mentioned elsewhere 458 express, 458 Lott, 458windbag
Gumpy

So, you’re not a fan of the.458 Win dbag then

 

[Riflecrank]

So almost nobody is making rifles to minimum SAAMI/CIP specs, judging by Larry's rifles.
The .458 Lott has backslid to longer throat ?
Well and good.
Just because the throat is longer than minimum does not mean it is out of spec.
So the .458 Lott has backslid to 1:14" twist also ?
That is OK too. No significant difference from the 1:10" homologation.
That little increase in twist to 1:10" caused less than 0.5 % increase in pressure or decrease in velocity.

Make up a dummy like this and run it into your ".458 Lott". If it chambers, then you are safe to fire .458 WM+ loads in your .458 Lott rifle:

Since the bevel on the base of that North Fork bullet is about 0.020" long, add that length to the dummies above, for the actual length of the dummy.
Make the actual dummies as close as possible to this:
.458 Lott: 3.0143" + 0.020" = 3.0343" = ~3.034"
.458 WinMag: 3.1725" + 0.020" = 3.1925" = ~3.193"

Those would be the GO gage lengths for throat.
If the .458 WinMag GO gage can be chambered in your .458 Lott, you are safe to fire ammo as powerful as the .458 WM+ handloads
in either your SAAMI Minimum-Throated .458 WinMag
or your SAAMI Plus-Throated .458 Lott.

Remember how Jack did his first .458 Lott Wildcat:

 

[Grumpy gumpy]

So, you’re not a fan of the.458 Win dbag then

I’ve got one, I built it 2015-16 for a buffalo hunt that didn’t eventuate. (Only fitted the open sights this year) I have taken several animals with it, deer, kangaroos (with permit) a couple of possums etc. it’s been to WBB a couple of times, but apparently 560gns at 2200fps is plinking loads according to some self appointed expert
Gumpy

 

[Riflecrank]

Anytime the cartridge is longer and more like a pencil the chance of feeding mishaps is greater.
The shorter .458 WinMag is going to be the better option overall.
That Browning Safari FN Mauser .458 WinMag with 3.4" magazine box length is utterly reliable in feeding with FN solids at 3.275" or shorter COL.
It balks on the second of three in the magazine at any COL longer than that.
Pointy bullets no problems at longer COL.
That 24"-barreled rifle will do +2200 fps with 500-gr TBSS at 3.270" COL and less than 60,000 psi.
Previous owner of the rifle got 500-gr Nosler Partitions up to 2300 fps at 3.340" COL, and what pressure I do not know, with excellent accuracy.
I do not need to do that. I think 2200 fps with either of those bullets is plenty.
And I will have better bolt-action-working speed with accuracy in emptying my rifle than if I had a .458 Lott.
Even if the Lott is only delivering 2200 fps MV with 500-gr bullets at longer COL, it is going to have to burn more powder to do it and require a longer bolt throw.

I would chose a COL of 3.380" or 3.390" (2.490" or 2.500" brass length) to load the 500-gr Nosler Partition to 2200 fps MV.
The 500-gr TBSS at shorter COL (3.270") and same velocity.
The 404-gr Hammer HPBT COL 3.380" and 2500 to 2600 fps.

The CEB Safari Solids would have to be loaded shorter at about 3.260": 450-grainer at 2350 fps, 400-grainer at 2500 fps: That is made possible by using Norma brass which has about a 4.5-gr H2O greater case capacity than the standard brass used in other loads above.

 

[Riflecrank]

I’ve got one, I built it 2015-16 for a buffalo hunt that didn’t eventuate. (Only fitted the open sights this year) I have taken several animals with it, deer, kangaroos (with permit) a couple of possums etc. it’s been to WBB a couple of times, but apparently 560gns at 2200fps is plinking loads according to some self appointed expert
Gumpy

I do not doubt 560-grainers at 2200 fps from the SAAMI-chambered .458 WinMag in your rifle.
I have done the same/more with cast bullets and excellent accuracy.
Gas-checked, powder-coat-painted, BHN 25 and sized to .461" in .458"-.459"-grooved rifles.
I do not call that a mere plinking load,
and I am a self-appointed expert.

Some of those cast bullets are so short and blunt that they can be fitted into a 3.340" COL or little more, but with more than 0.3" length of 0.461" diameter extending into the throat.
That is impossible in a .458 Lott that has only 0.459" diameter of very short, parallel-sided free-bore ahead of the 2.810" chamber length.
No length of .461" diameter cast bullet will chamber in a .458 Lott.
0.461" diameter bullet is required for best smokeless accuracy in the .458s.
The .458 Lott is a miserable cast-bullet shooter compared to the .458 WinMag,
especially if it has a 1:10" twist instead of the 1:14" twist of the .458 WinMag.

 

[CoElkHunter]

I’ve got one, I built it 2015-16 for a buffalo hunt that didn’t eventuate. (Only fitted the open sights this year) I have taken several animals with it, deer, kangaroos (with permit) a couple of possums etc. it’s been to WBB a couple of times, but apparently 560gns at 2200fps is plinking loads according to some self appointed expert
Gumpy

Kangaroos and possums with a 560gr. bullet? You should have been using your 6.5 Creedmoor for those and saved the big stuff for camels, scrub bulls and such in OZ. LOL

 

[CoElkHunter]

View attachment 649910

View attachment 649911

View attachment 649912

View attachment 649914

So almost nobody is making rifles to minimum SAAMI/CIP specs, judging by Larry's rifles.
The .458 Lott has backslid to longer throat ?
Well and good.
Just because the throat is longer than minimum does not mean it is out of spec.
So the .458 Lott has backslid to 1:14" twist also ?
That is OK too. No significant difference from the 1:10" homologation.
That little increase in twist to 1:10" caused less than 0.5 % increase in pressure or decrease in velocity.

Make up a dummy like this and run it into your ".458 Lott". If it chambers, then you are safe to fire .458 WM+ loads in your .458 Lott rifle:

View attachment 649907
View attachment 649908

View attachment 649909
Since the bevel on the base of that North Fork bullet is about 0.020" long, add that length to the dummies above, for the actual length of the dummy.
Make the actual dummies as close as possible to this:
.458 Lott: 3.0143" + 0.020" = 3.0343" = ~3.034"
.458 WinMag: 3.1725" + 0.020" = 3.1925" = ~3.193"

Those would be the GO gage lengths for throat.
If the .458 WinMag GO gage can be chambered in your .458 Lott, you are safe to fire ammo as powerful as the .458 WM+ handloads
in either your SAAMI Minimum-Throated .458 WinMag
or your SAAMI Plus-Throated .458 Lott.

Remember how Jack did his first .458 Lott Wildcat:

View attachment 649915

Your schematics and ballistic information is very interesting. Now take @Frederik 's .458 Express cartridge and stuff a bunch of RL15 (instead of slower powder) into it and make something extraordinary happen with it? LOL