The “458 Winchester Magnum, all the cartridge you’ll ever need” thread

[cajunchefray]

the 500gr projectiles offer significantly more penetration, especially when looking at solids. while bullets under 450gr may perform well in most situations, they lack the sectional density of the 500gr bullets. this is of course important for back up shots at fleeing or charging dangerous game.

Consider reading the thread by @michael458 regarding very detailed penetration tests with modern monumental FN solids400-450 grains (CEB) and Northfork versus old school 500 grain .458 solids, like Hornady or Remington.

The data is clear. Michael conducted engineering based tests, over hundreds of rounds fired in controlled experiments.
Then he tested these on dozens of dangerous game over several years, all with good results.

Sectional density, as a static measurement, is not the same as functional sectional density performance on game.
It’s an eye opener.

Monumental bullets, with an optimal 67% meplat, in the 400-450 weight range out penetrating conventional 500 grain RN solids every time. And straight line much better for more effective kills.
It’s something I learned, then forgot dozens of years ago.
A .357 magnum hard cast SWC will always out penetrate a RN, in a straight line every single time.
After you get a pass through, how much more do you need?
Hence drop down the bullet weight, load a great bullet design, less recoil.
His extensive testing is worth the read.

 

[cajunchefray]

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Empirical data.

Repeatable in other experiments. Richard Harlon and Ganyana did just this in the bush in Zim on a lot of elephants and buffalo.

Just consider the controlled variables and results.
Following the development of modern monometal bullets, African bullet companies launched the idea, and Western companies perfected these and brought them to the market.

Thanks @michael458 for a thorough scientific analysis.

 

[Ruraldoc]

If I want to hunt dangerous game and plains game with the same rifle, I just stick with my 416 Remington.

Using 400 Partitions spitzers for plains game or big cats and 400 grain A frames for Buffalo, plus solids as needed. My neighbor friend likes 400 grain bear claws and woodleigh hydros.

My longest shot is just short of 200 yards,but my friend has a bushbuck at over 300.

All of our ammo feeds from the magazine.

 

[ldmay375]

Consider reading the thread by @michael458 regarding very detailed penetration tests with modern monumental FN solids400-450 grains (CEB) and Northfork versus old school 500 grain .458 solids, like Hornady or Remington.

The data is clear. Michael conducted engineering based tests, over hundreds of rounds fired in controlled experiments.
Then he tested these on dozens of dangerous game over several years, all with good results.

Sectional density, as a static measurement, is not the same as functional sectional density performance on game.
It’s an eye opener.

Monumental bullets, with an optimal 67% meplat, in the 400-450 weight range out penetrating conventional 500 grain RN solids every time. And straight line much better for more effective kills.
It’s something I learned, then forgot dozens of years ago.
A .357 magnum hard cast SWC will always out penetrate a RN, in a straight line every single time.
After you get a pass through, how much more do you need?
Hence drop down the bullet weight, load a great bullet design, less recoil.
His extensive testing is worth the read.

Yep.
Being that sectional density was hammered into heads for over a century as being the foremost factor of penetration it is hard for many of us to face the reality of bullet design and construction. I was certainly slow to come to the water trough.

Michael went through a lot of time, expense, and bullshat to share factual unbiased information to the general populace. As well, as expending lots of patience in my case.

 

[odonata]

On the right track.
I have a Whitworth.458 that is a dream to handle and shoot.

But I still have an itch for a rebarrelled Ruger 77MKII. Solid action and I like the scope rings to milled action bases.

So far I've been really pleased with my Ruger 77 MkII so I would recommend it as an option to consider. The laminate stock on mine is slender especially in the forearm which some people may not like but feels good to hold in my hands. It may be a bit barrel-heavy with the balance point near the front crossbolt but I like the way it points & shoots. For me, it was a fun project to upsize a 7mm RM to a 458 Win Mag.

It was also an affordable way for me to get a bit more educated about rifles like this because none of my friends have anything like it that I could test shoot so I was coming in kind of blind. As they get older, all of them seem to be retiring their bigger rifles and going for milder shooting rounds. I'm the only oddball who is enthusiastically going in the heavier direction.

 

[cajunchefray]

Empirical data.

Repeatable in other experiments. Richard Harlon and Ganyana did just this in the bush in Zim on a lot of elephants and buffalo.

Just consider the controlled variables and results.
Following the development of modern monometal bullets, African bullet companies launched the idea, and Western companies perfected these and brought them to the market.

Thanks @michael458 for a thorough scientific analysis.

To clarify my recent post:

Correction:
Richard Harland (sp.) did not specify use of monometal solid bullets in the .458 Win Mag but referenced using lighter than 500 grain bullets in a 458 WM Mannlicher for elephant culling.

Source: "African Dangerous Game Cartridges, Pierre van der Walt, page 326.

The reference to Ganyana (Don Heath) is from other sources.
"Nyati : the Art of Hunting the African Buffalo page 109",

Mr. Heath references Zimbabwe Parks purchasing A-Square Monolithic Solids for elephant culling in 1991. From other sources this was 465 grain monolithic solids. Mr. Heath chrono graphed these in 1996, still in spec at 2170fps +/-.
10 years later, the ammo chrono graphed at circa 1780 fps (powder problems).
Fresh ammo was good, old ammo, old school powders, not so.

Both men killed a lot of elephants with the 458 Win Mag, later in their careers, with optimized weight monometal bullets.

 

[Flewis]

On the right track.
I have a Whitworth.458 that is a dream to handle and shoot.

But I still have an itch for a rebarrelled Ruger 77MKII. Solid action and I like the scope rings to milled action bases.

It’s funny you say that as my gunsmith is doing that exact setup for me. The only thing we are going over is sights.

 

[Northern Shooter]

Glad we've had such lively debate on this topic, looks like many here enjoy the 458 as much as I do.

I think I may just dig it out of the safe for White Tail season next week.

 

[BourbonTrail]

If I want to hunt dangerous game and plains game with the same rifle, I just stick with my 416 Remington.

Using 400 Partitions spitzers for plains game or big cats and 400 grain A frames for Buffalo, plus solids as needed. My neighbor friend likes 400 grain bear claws and woodleigh hydros.

My longest shot is just short of 200 yards,but my friend has a bushbuck at over 300.

All of our ammo feeds from the magazine.

I shot @Riflecrank ‘s 458 WM, and it was no worse than my 416 Rem. His 500 Mbogo is a different story.

That said, the 416 Rem is also my preference for an all around cartridge.

 

[Don458]

Just a Heads up -There is a whitworth .458 on GB. New with box and manual https://www.gunbroker.com/item/1072003185

 

[Slyfox72114]

And mention that the .458 WinMag is operating at 60,000 psi MAP and 3.34" COL
while the .458 Lott requires 62,500 psi MAP and 3.6" COL, and even at that it has trouble getting to claimed velocity.
The .458 WinMag has no trouble at all.
That is the Hornady DGX/DGS load for the .458 WinMag.
I have chronographed it in about a half dozen 24"-barreled rifles. Just about spot on in all of them,
except it gave 2196 fps MV in a 24-inch barrel with a shorter throat on the otherwise SAAMI .458 WinMag chamber, though it still had twice the throat length of the SAAMI .458 Lott.

If I load my .458 WinMag with maximum .458 Lott loads and COL about 3.56" I still have room to pour it on.
500-gr TBSS FN at +2400 fps from a 24" barrel by LabRadar, before I had a Garmin XERO,
that is what we call the .458 WM+. That was in a factory Ruger No. 1 .458 WinMag.
If you want to get kicked harder than by a .458 Lott you can easily beat it with a SAAMI-chambered .458 Winchester Magnum.

Oh boy, don't get me started on the .458 Lott propaganda.

This seems like a savvy lot here! I’ve never been in a thread before so forgive me if I’m breaking protocol here.
I have a 458 question possible problem.
I recently purchased US 1917 Eddystone
P O Ackley improved 458. It’s a sharp looking rifle that looks hardly handled it’s neat and clean. my problem is after disassembling the gun there’s no evidence it’s a PO Ackley 458 other than what the owner said which was the father or grandfather bought it direct from PO Ackley gun shop.
I wanted a simple big bore rifle open sites to take to Africa for Cape Buffalo. Question is should I just shoot a 458 Lott or for 458 WinMag through the rifle or reload the actual Ackley bullet which will require some doing?
Seems some practice rounds from Lott/Win mag is doable. Just not sure what I should do and need some advice from 458 people Thanks in Advance!

 

[Riflecrank]

Hello Slyfox,
Is the rifle not marked as a "450 Ackley Magnum" ?
That is the one we think of usually.
It came along after James Watts started it all with his ".450 Watts Magnum," shooting first in 1949.
Watts visited Ackley and Buhmiller, looking for a barrel early on in his dreaming stage.
It does seem Watts beat both of them to the .450-bore on the 2.85"-length H&H Magnum case.

The .450 Watts Magnum has a straight, belted case, no shoulder, and is 0.050" longer than the .458 Lott wildcat latecomer (1971).

The .450 Ackley Magnum had a 2.85" belted H&H case length also, but had a tiny shoulder located at 2.407" from the base face of the brass case.
Shoulder hemi-angle angle was 20* (cone angle 40*).
Shoulder was 0.503" diameter at 2.407" length.
Neck-1 was 0.487" diameter at 2.429" length.
Neck-2 (case mouth) was 0.486" diameter at 2.850" maximum brass length.

If you have a .450 Ackley Magnum, it really would be best to get the proper handloading dies and some basic cylindrical H&H Magnum brass to size down and shoot, and some properly headstamped brass for Africa. And the rifle needs to be engraved/stamped properly as to chambering/cartridge on the barrel.
The .450 Ackley Magnum is well known and bragged about often by magnificent author Terry Wieland. Proper brass and dies should not be too hard to find. Google away.

I have a .450 Barnes Supreme by Fred N. Barnes, from the 1950s, which is very similar to the .450 Ackley Magnum. Barnes used both Brevex and 1917 Enfield actions for the Barnes Supreme line of proprietary cartridges he offerred.
Long brass, tiny shoulder, load data would be interchangeable.
I also have a .416 Barnes Supreme, another one from the 1950s.
Both of my Barnes Supremes were built on Whitworth MK X actions in 1987, just before Remington came out with the .416 RemMag, boo-hoo.

Watts also did a 2.5" .450 Watts Short before the .458 Winchester Magnum was released to the public in 1956, after James Watts "released " it to Winchester in the year 1954 or before.

Fred N. Barnes was offering his proprietary 450 B-J Express (Barnes-Johnson) in a lineup of "short magnum" cartridges from 7mm to .458 caliber, in the early 1950s.
He claimed his 450 B-J Express was being chambered and rifles sold "several years before Winchester added the .458 to their line."
The B-J express line all had 2.5" belted H&H Magnum ("short magnum") cases with the case body length to shoulder being 2.125", shoulder diameter 0.500", shoulder hemi-angle 35*.
He said in his March 15, 1958 pamphlet:
"450 B-J Express
The most powerful of the B-J Line. Shoots a 500 gr. bullet at 2200 f.s. Works perfectly in any standard length action. Rifles chambered for this cartridge will also shoot the new .458 Winchester factory cartridge.
While this is a so-called improved version of the .458 Winchester we chambered rifles for the .450 B-J several years before Winchester added the .458 to their line."

Seems Fred N. Barnes might have given Winchester ideas about the .338 WinMag and .264 WinMag too.

So when you say "improved .458" it stirs up thoughts of something other than the .450 Ackley Magnum.
Most likely it is a .450 Ackley Magnum if built on a 1917 Enfield and has a +3.6" magazine box internal length.
Mind your P's and Q's and get a chamber cast if any questions.
Firing a factory .458 Lott cartridge in your rifle to get a short-necked version of the .450 Ackley Magnum would be a sort of chamber cast, in brass.
An actual chamber cast would tell you more about the throat.
Lacking that, check the throat length with dummy cartridges using .458 Lott brass before shooting it.

 

[Safari Dave]

You can complicate it, or you can just shoot factory Hornady DGX's and you will be just fine.

If your PH want's you to use a few solids, just buy a box of Hornady DGS's.

(My .416 Rigby shot them to the same POI.)



Shoot a few rounds at 50 yards, and if they are all close, don't worry about it.

.458 Winchester Magnum inadequacies ceased to exist 30 years ago.

 

[michael458]

I'm a total noob, so I apologize if you have answered this question before. At what depth of penetration in your test medium did you consider enough?

No apologies needed at all. In fact, it is an excellent question. It was the same question I had when I first started testing bullets some 30 years ago.

Let me define the medium and tell you why I decided to use the medium that I use.

In the very early years of test work I used straight wet news print. Medium has to be aqueous, animal tissue is aqueous, animals are not made of wood or dry material. To have any sort of simulation the medium has to be aqueous or you are testing something else.

At some point in the early days every day I would get the mail, there were 3-4 inches of catalogs that came to my wife! Its like we were being over run with these things, and I decided to see if I could incorporate some of these in the test work. It was a fluke, but what I learned is that if I used 2 inches of this catalog mix every 10 inches of total medium, it made a very dense, very tough medium on all bullets. Far tougher and more dense than animal tissue. Mind you, this medium was very well soaked, sometimes for days. I believe the introduction of these magazines/catalogs made the overall mix somewhere around 30% tougher/denser than straight wet print.

Now, the point is to STRESS the bullet, so you don't want to be EASY on it, you want to give it a hard test, a test that will show any short comings of design. But also not something that is not realistic, and something that can be repeated over years of different tests for real comparisons between designs.

We moved into our Indoor Facility about 20 years ago. Top of mind was doing bullet research so the back of the range was designed to do this, with drains in the floor for water to exit as the boxes were soaked daily. The first box built was held 65 inches of test medium. After we started testing some of the #13s and a few other designs, I found I needed a second box to catch some of these bullets, I had a few exit 65 inches.....

We had tested a lot of Round Nose Solids.......... RN are not stable during terminals....... I had a joke about setting up the boxes to test RN.......

We also used what I refer to as "Witness Cards", I took card stock paper, laminated it, and would insert into the mix at regular intervals to assist in showing me what was happening with a bullet at each depth. With trauma bullets cards were closer together. With Solids I would insert every 10 inches. These were measured extremely carefully so that each card was placed exactly the same all the way through the test medium. When you tested a Solid, you were then able to pull each Witness Card and tell exactly if you had straight line penetration all the way through, or if the bullet tended to veer off course, even slightly............

I think this is an example used for a trauma inflicting bullet...........

What all the test work did for us is show us bullet behavior in aqueous medium, potential failures and successes of different designs with both Solids and Trauma Inflicting bullets, and it showed us exactly how a particular bullet behaved, and how different design changes effected Terminal Performance.

Once proven in the test work, it was time to take it to the field. While we gained incredible knowledge in the test work, we learned even more in the field. Animal tissue and tested not only confirmed the test work, but showed us even more of how the bullet actually worked. It was an incredible journey.

Now, back to the Question at hand.......

At what depth of penetration in your test medium did you consider enough?

Years of digging bullets from animal tissue, solids, conventional softs, Generation 1 and Generation 2 CNC Trauma inflicting bullets, we began to put together a "Rule of Thumb" for each of these. Rule of Thumb is not absolute by any means, there are many factors that you will encounter in the field that cannot be duplicated with certainty on the range or in test work. Just one example, Bone!

With this in mind my Rule of Thumb for

Conventional Expanding Bullets is 70% more penetration in Animal Tissue than the Test Medium I use.

Gen 1 and Gen 2 CNC Trauma Inflicting bullets 100% more penetration in animal tissue than in the test medium.

SOLIDS 35% more penetration in animal tissue than in the test medium.

So the question is, How Much Penetration is needed in Animal Tissue?

How many inches is a buffalo broadside? Elephant Broadside? Hippo?

How about if you need a Solid from the rear to reach vitals of a fleeing buffalo? Elephant?

Frontal or side brain shots on elephant?

I won't tolerate Solids that do not drive dead straight. Only dead straight will give you reliable penetration and stability to accomplish the mission. Most proper designed big bore solids meant for serious work, elephant, buffalo, hippo, will drive 55-65 inches in the test medium dead straight.
This gives us Rule of Thumb 7-8 feet of penetration in animal tissue. And a pretty solid chance that we can get to the vitals even from some rear shots. Definitely on buffalo, carefully on elephant. I have had some of my .500 caliber rifles end to end elephant and exit. That is most comforting to know, in those worst case scenarios. In many cases to be quite honest, I also think my 35% for Solids is conservative for some designs.

In the example of some Lever Gun Solids, in particular the #13 CEB Design, they test at 40-45 inches. And this puts them at 5-6 feet of animal penetration, and that is nearly spot on from what I have seen on hippo and buffalo. But lets say elephant was on the menu, 5-6 feet, I would be very cautious about a rear end shot, I would take it if I had to, but it would be in the back of my mind. Broadside heart? No issue at all.

So such a complicated answer, for such a simple question....... But a much needed base of knowledge to work with. An excellent question.

Simple answer from me and for me............. How much is Enough? I always wish for more than enough!

 

[odonata]

@michael458, I wish I could give the previous post more than one “Like”. Very informative.

 

[Cheesehead]

That's the answer I was hoping for and then some! Thank you!

 

[VertigoBE]

@michael458: thanks again for all your wonderful insights.

What caught my eye a bit more this time is the fact that you discovered that, with the right bullet construction, a lower weight (than typical) bullet can be used and still achieve very good penetration results.

The advantages of a lower weight, main one I would see is lower felt recoil, so it should allow, practically speaking, for better shooting by hunters.

I believe you once mentioned that it was a colleague of you who is an expert on double rifles. As you know double rifles can be a bit meticulous about their loadings, in order to regulate. Do you know or know of, any tests that were made where a double rifle, regulated for the standard weight for the caliber, with older bullet designs, could be made to regulate with lower weight new bullet designs?

A second question I have on the weight of bullets is:
Your tests, both in the lab and in the field, showed that current bullet designs with lower weight performed more than adequately, in the wet paper boxes and on animals. Yet you also always make an asterisk around bone, since there is too much variability there to enable consistent testing. Have you noticed any potential performance issues between two bullet weights of modern design, when encountering bone however? (therefore perhaps still somewhat validating the notion that higher weight does help with performance) Or is there no "noticeable" difference?

 

[michael458]

As you know double rifles can be a bit meticulous about their loadings, in order to regulate.

OK how about we call a spade a spade.......... Instead of a really nice word, "Meticulous" how about we say Pain In The ASS.......... or can be.

Short story..... my Pal Sam and I had been doing extensive research, load data and pressure data and barrel strain data on a 500 NE. So much so, that I had kept the rifle here to continue with it on some days he was not available. He messaged me to get a load ready and regulated because he wanted to get this rifle ready for a hunt. Man I had a load that would put both barrels in the same exact hole at 25 yards....... Over out and done as far as I was concerned. He pitched up, we shot the rifle, and they were 8-10 inches apart for him at 25 yards????? WTF??? I knew this could not be so. I took the rifle, I shot the rifle right next to him, and again, right/left in the same hole, dead center at 25 yards???? In the end, we determined it was simply how we held the rifle differently, we repeated this over and over........ I made my mind up then and there, I don't need a double of any sort....... Meticulous? Hmmmm......... Yep.

Do you know or know of, any tests that were made where a double rifle, regulated for the standard weight for the caliber, with older bullet designs, could be made to regulate with lower weight new bullet designs?

Oh yes, many times over............ I know of many 500 NE guns that regulate perfectly, maybe even better with the 510 CEB Solids and the 475 Raptors............ I have had many friends use these on buffalo, elephant and hippo in many different guns. Also, my pal Sam uses a CEB 650 gr Solid and 600 Raptors in his 577 NE and has for years........ zero issues to regulate...... Anyone that is in my circle and has double rifles have not had any issues at all with these sort of bullets, I can't speak for other types bullets.

Have you noticed any potential performance issues between two bullet weights of modern design, when encountering bone however? (therefore perhaps still somewhat validating the notion that higher weight does help with performance) Or is there no "noticeable" difference?

A very good question. I honestly think I may not have a definitive answer for this. My personal experience with 458 caliber has been the 450 weight class and a lot of CEB #13s...... early days both 450 Barnes FN and 500 Barnes FN. When it came to crunching bone, I never had any issues with the 450 #13s crunch and munch their way through whatever. A good friend of mine used his 458 B&M 18 inch gun and a 450 #13 Solid to crunch the hell out of an elephant, I had never seen one so broken, both sides I think busted through both shoulders, and still exited.......

Mind you this 450 #13 was only around 2200--2225 fps, and broken this elephant down completely in the entire front end, both sides. I don't see a heavier bullet doing any better than this? And still exited..........

I have shot quite a few buffalo, hippo and elephant with my various .500 caliber rifles/cartridges and they have been hammers. Lighter .500 caliber 450 and 500 gr Solids are devastating and crunch and munch about anything in their path. I have had some contact with heavy bone and you can get some distortion, but they still accomplish the mission.......

The bullet on the far left has some distortion after beating a hippo to pieces......

This bullet crunched some heavy bone on the shoulder......

Those 405s are in my Lever gun in 50 B&M Alaskan......... .500 caliber.

My opinion about heavier crunching bone, heavier can't hurt. But I have never seen where it was required or specifically needed because I came up short with lighter........

 

[cajunchefray]

As you know double rifles can be a bit meticulous about their loadings, in order to regulate.

OK how about we call a spade a spade.......... Instead of a really nice word, "Meticulous" how about we say Pain In The ASS.......... or can be.

Short story..... my Pal Sam and I had been doing extensive research, load data and pressure data and barrel strain data on a 500 NE. So much so, that I had kept the rifle here to continue with it on some days he was not available. He messaged me to get a load ready and regulated because he wanted to get this rifle ready for a hunt. Man I had a load that would put both barrels in the same exact hole at 25 yards....... Over out and done as far as I was concerned. He pitched up, we shot the rifle, and they were 8-10 inches apart for him at 25 yards????? WTF??? I knew this could not be so. I took the rifle, I shot the rifle right next to him, and again, right/left in the same hole, dead center at 25 yards???? In the end, we determined it was simply how we held the rifle differently, we repeated this over and over........ I made my mind up then and there, I don't need a double of any sort....... Meticulous? Hmmmm......... Yep.

Do you know or know of, any tests that were made where a double rifle, regulated for the standard weight for the caliber, with older bullet designs, could be made to regulate with lower weight new bullet designs?

Oh yes, many times over............ I know of many 500 NE guns that regulate perfectly, maybe even better with the 510 CEB Solids and the 475 Raptors............ I have had many friends use these on buffalo, elephant and hippo in many different guns. Also, my pal Sam uses a CEB 650 gr Solid and 600 Raptors in his 577 NE and has for years........ zero issues to regulate...... Anyone that is in my circle and has double rifles have not had any issues at all with these sort of bullets, I can't speak for other types bullets.

Have you noticed any potential performance issues between two bullet weights of modern design, when encountering bone however? (therefore perhaps still somewhat validating the notion that higher weight does help with performance) Or is there no "noticeable" difference?

A very good question. I honestly think I may not have a definitive answer for this. My personal experience with 458 caliber has been the 450 weight class and a lot of CEB #13s...... early days both 450 Barnes FN and 500 Barnes FN. When it came to crunching bone, I never had any issues with the 450 #13s crunch and munch their way through whatever. A good friend of mine used his 458 B&M 18 inch gun and a 450 #13 Solid to crunch the hell out of an elephant, I had never seen one so broken, both sides I think busted through both shoulders, and still exited.......

View attachment 644002

View attachment 644003

Mind you this 450 #13 was only around 2200--2225 fps, and broken this elephant down completely in the entire front end, both sides. I don't see a heavier bullet doing any better than this? And still exited..........

I have shot quite a few buffalo, hippo and elephant with my various .500 caliber rifles/cartridges and they have been hammers. Lighter .500 caliber 450 and 500 gr Solids are devastating and crunch and munch about anything in their path. I have had some contact with heavy bone and you can get some distortion, but they still accomplish the mission.......

View attachment 643997

View attachment 643998

The bullet on the far left has some distortion after beating a hippo to pieces......

View attachment 643999

This bullet crunched some heavy bone on the shoulder......

View attachment 644000

View attachment 644001

Those 405s are in my Lever gun in 50 B&M Alaskan......... .500 caliber.

My opinion about heavier crunching bone, heavier can't hurt. But I have never seen where it was required or specifically needed because I came up short with lighter........

@michael458 great post, as always.
Do you think that the faster twist rate (1:12") in the .500 MDM, 405 grain BBW Solid, accounts for more effective penetration?

I read and study reports such as yours, and others such as Pierre van Walt in African Dangerous Game Cartridges.
There is a good, scientific explanation of the effectiveness, in test media, of a broad meplat bullet, or proper monometal metallurgy (67% meplat as you have found), with a faster twist rate, that better stabilizes a bullet in terminal media, and effectively "ups" the sectional density factor for penetration. And breaks bone.

It seems that your data, from extensive controlled scientific tests, then real world suggests this.

What do you think?

 

[michael458]

There is a good, scientific explanation of the effectiveness, in test media, of a broad meplat bullet, or proper monometal metallurgy (67% meplat as you have found), with a faster twist rate, that better stabilizes a bullet in terminal media, and effectively "ups" the sectional density factor for penetration.

Yes, I would concur with that statement..........100%........... Think about this, much of the time the solid is going to be needed at very close ranges, the quicker you have aerial stability before going terminal, the better off you are going to be. Damn sure can't hurt anything.

Twist rates are a major factor in the stability of solids, and more so for less than .458 caliber. In .416 caliber 1:12 is very good. 1:14 barely gets you there with 400s and they loose stability in the last 5%-10% of total penetration in .416s. 1:12 fully stable.....

Do you think that the faster twist rate (1:12") in the .500 MDM, 405 grain BBW Solid, accounts for more effective penetration?

Yes, no doubt about it, makes a big difference. The first .500s were 1:18 twist. I had lots of conversation with JD about this and we made the move to the 1:12 PacNor barrels, and it made a huge difference in stability during terminals, giving straight line penetration.

You will notice the faster twist rates with less than desirable designs, bullets that have smaller meplat sizes and even RN solids. The faster twist rates will give a bit better straight line performance, a few inches in the tests. These bullets will still destabilize regardless during terminals. But you can gain a small amount with the faster twist.

A good and proper designed solid will self stabilize itself during terminals for 85% to 90% of its overall depth of penetration.... Caliber .458 + and meplat sizes above 65% of caliber. I have had rifles with oversized barrels and proven this. Twist rate is less important with proper designs and meplat sizes 65% or better and .458 caliber or larger.

In .458 + I like either 1:10 or 1:12 is great, you can get by at 1:14, most of my 458s are 1:14. All myu .500s are 1;12. If you are building 416s, or less than .458, definitely without doubt you need 1:12.

I hope we have not strayed too far from "458 Winchester"............... I will add this to get back on track.............."Magic Begins at .458 Caliber" and you will never require or need more than what 458 Winchester can give you...... Rule the World with Authority.

Don't forget the new Generation trauma inflicting bullets in .458............ I am very fond of a certain 250 gr Socom Raptor........ Hmmmm?................. and there are many more........ turn your 458 Winchester into a very versatile power house............