Test to see if THE MISSION page turns to 209.
Edit: Yep.
Only about 60 replies have vanished out of about 8360.
The cabal of evildoers has been at it again.
That is just prolonging THE MISSION.
Doing good has no end.

.458 Winchester Magnum Perfection
In maxima potentia parvum spatium.
Id venit et vicit omnis.

Ron,

I posted yesterday our time and while not showing directly on the thread it is there when I go to my profile and forum posts.

posted 04 August 2020 00:58 (Sydney time) Hide Post
quote:
Originally posted by .458 Only:
RIP;

The 543-gr at 1382 fps = 140 MTE is the same as my former .340 WBY shooting a 250 at 3000 fps or my 9.3 x 62 firing the 286-gr at 2622 fps.

Something to think about, and I have.

Bob
www.bigbores.ca


A science thought on momentum/animals and conservation of momentum and assuming bullet stays in animal. When the bullet stops its momentum is zero but the momentum of flesh/bones (and hide) wil equal the momentum of the bullet. So a bullet with bigger momentum could either mean a bigger weight of flesh/bone moving at the same velocity as caused by bullet of lower momentum or could result in the same weight of flesh/bone moving but moving at higher speed than that caused by the bullet of lower momentum.

quote:

Originally posted by RIP:

I like the mold, but does it make sense to have two bullets which require different alloys in the same mold?
Seems like the PP cavity being .450" (to patch up to .458") would be better if poured of the same alloy as the GG bullet.

Shooting a bore dia. bullet with black powder works best if the chamber is cut to just allow a bore dia. patched bullet or not much bigger.
The 458WM chamber is made for a .458" projectile so the neck will be loose in the chamber when using a .450" patched bullet.
If your patched bullet is groove dia. it will run with black or smokeless powder in just about any alloy.

Huvius, buy a donkey for the reply.

quote:

Originally posted by Huvius:
I like the mold, but does it make sense to have two bullets which require different alloys in the same mold?

Not a really bright idea, but it only cost $15 extra to put two different bullets in one 2-cavity mould, instead of identical cavities.
I will have two pots and two dippers with the different alloys in them, and hope to be coordinated enough to pour them correctly.
That would be soft alloy for BPCR PP slick, and hard alloy for smokeless FNGC.
Sprue plate is standard, no trough between the holes.

Seems like the PP cavity being .450" (to patch up to .458") would be better if poured of the same alloy as the GG bullet.

True. The PP slick diameter is .442" -.000/+.002". Bill and Jerry have had their way with me for the PP bullet diameter, same as Ross Seyfried did with his .461 Gibbs, and I am sure you would approve of that, for BPCR shooting.
This PP is primarily for various .45-70 rifles, the remnants of my sanity.
I did use .451"-.452" slicks successfully in the .45-100-2.6" Winchester-Throated,
swaged ones from BACO.
Something new now, making my own for .45-70.

Shooting a bore dia. bullet with black powder works best if the chamber is cut to just allow a bore dia. patched bullet or not much bigger.
The 458WM chamber is made for a .458" projectile so the neck will be loose in the chamber when using a .450" patched bullet.
If your patched bullet is groove dia. it will run with black or smokeless powder in just about any alloy.

That is good to know.
Similarly sharpsguy (Bill) shoots the same grease-groove bullet at groove diameter (or -.001") in his Sharps rifle, with BP and IMR-3031.

I might have to get a .450" slick mould (-.000/+.002") for the .458 WIN neck&throat,
and it would have to be 570-gr in WW as a guesstimate.

.458 Winchester Magnum Perfection
In maxima potentia parvum spatium.
Id venit et vicit omnis.

quote:

Originally posted by Mike McGuire:
Ron,
A science thought on momentum/animals and conservation of momentum and assuming bullet stays in animal. When the bullet stops its momentum is zero but the momentum of flesh/bones (and hide) wil equal the momentum of the bullet. So a bullet with bigger momentum could either mean a bigger weight of flesh/bone moving at the same velocity as caused by bullet of lower momentum or could result in the same weight of flesh/bone moving but moving at higher speed than that caused by the bullet of lower momentum.

Mike,
Conservation of momentum, aye, I get it. More bullet momentum, more pushing at whatever it impacts.
It could move more tissue mass, or same tissue mass more violently than a bullet of lesser momentum.
Plumb Newtonian !
Now consider Einstein: If that bullet could travel at the speed of light it would have infinite mass AND infinite momentum,
and for the observer riding on that bullet, time would stand still.
Not too likely to happen, eh ? Not even with a .458 WIN.

.458 Winchester Magnum Perfection
In maxima potentia parvum spatium.
Id venit et vicit omnis.

Yes Ron, the speed of light is beyond even the 458 Winchester.

Below the math, observationally, the large flat point cast bullets kill so well because of their ability to move flesh and bone in front of them and to a lessor degree away from them. A .430 Keith SW going through a shoulder bone of an Elk at maybe 1000 FPS can Put a 3 inch hole through the lungs putting the elk down in a 50 yard death sprint. It wasn’t energy that did that. It was the efficiency of momentum.
Sharpsguy has given us plenty of anecdotal evidence of that Sam action.

quote:

Originally posted by Fury01:
Below the math, observationally, the large flat point cast bullets kill so well because of their ability to move flesh and bone in front of them and to a lessor degree airway from them. A .430 Keith SW going through a shoulder bone of an Elk at maybe 1000 FPS can Put a 3 inch hole through the lungs putting the elk down in a 50 yard death sprint. It wasn’t energy that did that. It was the efficiency of momentum.
Sharpsguy has given us plenty of anecdotal evidence of that Sam action.

One thing many peope forget when it comes to two bullets that both exit, is they think since they both existed the results shoud be the same and especially when talking abot FMJs or solid copper/bronze bullets. However, a heavier bullet in the same bore size hiiting at the same velocity will have a higher averge velocithy through the animal.

No doubt about the flat point bullet.

quote:

Originally posted by Mike McGuire:

quote:

Originally posted by Fury01:
Below the math, observationally, the large flat point cast bullets kill so well because of their ability to move flesh and bone in front of them and to a lessor degree airway from them. A .430 Keith SW going through a shoulder bone of an Elk at maybe 1000 FPS can Put a 3 inch hole through the lungs putting the elk down in a 50 yard death sprint. It wasn’t energy that did that. It was the efficiency of momentum.
Sharpsguy has given us plenty of anecdotal evidence of that Sam action.

One thing many peope forget when it comes to two bullets that both exit, is they think since they both existed the results shoud be the same and especially when talking abot FMJs or solid copper/bronze bullets. However, a heavier bullet in the same bore size hiiting at the same velocity will have a higher averge velocithy through the animal.

No doubt about the flat point bullet.

Choose any KE you want - say 2000 ft-lbs at impact, multiply by cross-section-area of bullet times SD (my formula). Then change the SD to a higher number and compare results. The higher SD (heavier in relation to diameter) will always give a greater result whether in penetration or total destruction depending on construction and bullet profile.

The formula assumes proper bullet construction and shape (flat tip?) for the MV and potential range.

If in Africa for dugga boy at 60 meters max, controlled by your PH? Do the math, or use what has proven itself under diverse conditions.

Personally, I have to use a scope, not a ladder!

Bob
www.bigbores.ca

quote:

The 543-gr at 1382 fps = 140 MTE is the same as my former .340 WBY shooting a 250 at 3000 fps or my 9.3 x 62 firing the 286-gr at 2622 fps.

There is also a velocity factor to consider for projectiles impacting at > 2600fps.

If the 340 Weatherby shot 250gn at 3000fps accurately. It would be a greeat all-around load.

(Personally, I tend to treat the 340 as a 4500ft# cartridge. 5000ft# is quite a step up, 338Lapua territory. For our discussions here, I use the data as presented.)

I don't think that there is any formula that one can use to totally predict how effective any bullet will perform on any game animal. It's simply not possible to do so.

The best we can do is to use different ones and compare notes, which is what many in this forum do!

As an extreme, I once saw someone blast a small groundhog with a .30-06 with a 125 grain soft at 100 yards - and blew the little animal's guts out. Yet, it refused to die and tried to crawl off. Thought it was dead, went downrange, and it was still trying to crawl off. I finished the poor thing off with a 9mm in the head.

I've also seen deer hit with a shot from a .270 drop dead right there. Same with a .243, .223, or .45-70. And some that just won't die.

The best we can do is to try different combinations and compare what works vs what doesn't most of the time, and go in the direction of what does.

And remember, your mileage may vary.

quote:

posted 06 August 2020 13:52 Hide Post
I don't think that there is any formula that one can use to totally predict how effective any bullet will perform on any game animal. It's simply not possible to do so.

Agreed. At best our attempts to quantify sweep the outliers off the table. The reason why is the variable of the target animal and it’s response to the bullets actions. That and we humans tendency to seek perfection in ourselves thus in our “science.”
We could say “yes that makes sense” like Bob’s work and carry on with that data point in our logical thinking but most of us respond to our urges for perfection and out goes the baby with the bath water.

quote:

Originally posted by 416Tanzan:

quote:

The 543-gr at 1382 fps = 140 MTE is the same as my former .340 WBY shooting a 250 at 3000 fps or my 9.3 x 62 firing the 286-gr at 2622 fps.

There is also a velocity factor to consider for projectiles impacting at > 2600fps.

If the 340 Weatherby shot 250gn at 3000fps accurately. It would be a greeat all-around load.

(Personally, I tend to treat the 340 as a 4500ft# cartridge. 5000ft# is quite a step up, 338Lapua territory. For our discussions here, I use the data as presented.)

Rifles are specific, they respond as individuals. Mine was a semi-custom (a .338 Win Mag rechambered with the Weatherby long freebore) with a 26" barrel and a tight bore.

That load was used for ten years without any issues. The only propelland that would do that was RL-22.

Weatherby now loads a 250 Partition in their factory load to 2950 fps from a 26". Originally it was 2850 fps.

Several reloading manuals claimed it was little better than a .338 Win Mag; and SPEER showed loads less than the .338 Win. Why? Because they were not tested for pressure.

That same barrel as a .338 Win produced 2842 fps from a 250gr Hornady SP from a book load of RL-19, prior to having it rechanbered. Read my blogs -- it's all there.

Bob
www.bigbores.ca

quote:

Originally posted by The Maz:
I don't think that there is any formula that one can use to totally predict how effective any bullet will perform on any game animal. It's simply not possible to do so.

The best we can do is to use different ones and compare notes, which is what many in this forum do!

As an extreme, I once saw someone blast a small groundhog with a .30-06 with a 125 grain soft at 100 yards - and blew the little animal's guts out. Yet, it refused to die and tried to crawl off. Thought it was dead, went downrange, and it was still trying to crawl off. I finished the poor thing off with a 9mm in the head.

I've also seen deer hit with a shot from a .270 drop dead right there. Same with a .243, .223, or .45-70. And some that just won't die.

The best we can do is to try different combinations and compare what works vs what doesn't most of the time, and go in the direction of what does.

And remember, your mileage may vary.

Sure, we've all experienced anomalies -- not the norm! But that doesn't change any fact of ballistics as to potential, and that's the reason for ballisticians of various companies giving ballistic results in manuals and factory ammo.

My thinking on this began about the time I purchased my first moose license. I would be hunting a bull moose in N. Ontario where I'd never previously been. But I had a general idea of conditions. I'd not be using a pro guide.

After I purchased my tag in Toronto at the MNR headquarters, I stopped by a classroom where a presentation was being made by an MNR official and officer on moose hunting firearms to a group of would-be moose hunters. It was more interesting than I thought.

He said, in so many words, that if using a .30-06 with a 180gr (factory load assumed) that they recommended 2 ft-lbs of energy at impact for every pound of moose, assuming a good hit in vitals. That would be 2000 ft-lbs from a 180gr/.30-cal for a 1000 lb moose. But since moose vary in sizes and weight all the way to a possible 1400 lbs, and are not necessarily standing broadside, one may want a rifle and load that compensates for a non-perfect shot placement, and at potential longer ranges than average, or expected. So a .300 Win would be better than a .30-06 under conditions less than perfect!

The lecturer was NOT a rookie!

I paid attention and began some basic calculations. He implied that larger calibers were better than smaller.

I've shot far more woodchucks than any other creature, and that taught me a few important lessons.

The point about the potential capabilities of the .458 Win Mag is that if a reasonable bullet and load is chosen for the task, poor results are not to be blamed on the bullet and load. As mentioned, the animal may decide to move as the trigger is squeezed, or an unseen obstacle might interfere, as in cases I've cited, or the hunter might pull the shot, or...

But none of those variables has anything to do with the rifle and load's ballistic potential.

So let's not confuse apples with oranges!

Bob
www.bigbores.ca

Bob,

Great the way you brought that back to the .458 WIN.
Anytime we start talking about "lethality indices" we calculate based on the flying bullets ballistics,
of course it is subject to impossible-to-predict
happenings of many more variables than the index accounts for.
But they can be a useful place to hang the thinking cap.
Bob's MTE is a better variation on the A-Square Penetration Index, adjusted to range at impact.

PI = (KE/CSA) X SD ... This correlates only with penetration at muzzle velocity of the cartridge's projectile.

MTE = KEI X CSA X SD ... This correlates with smack-down at whatever range it is applied to the load.

MTE is about as good as it gets IMHO.
I say that as the inventor of the Bwana Saeed Index, which is the Taylor K.O. multiplied by sectional density.
I acknowledge the limitations of that by calling it the BS Index,
but I do indeed consider it better than mere TKO,
though nowhere near as useful as Bob's MTE.

Buy a donkey to all for carrying on THE MISSION.
I have been a bit distracted recently by prenatal-self-counseling regarding the impending birth of the .500 Jeffery Match baby.

Regarding the incomparable .458 Winchester Magnum: I will next be shooting the hardcast 570-grainer



in further pursuit of double-bullet regulation of the .458 WIN.
I forsee hunting anything and everything with a .458 WIN and cast bullets.

I have become jaded by the ease with which jacketed and monometal copper and brass bullets can be used in the .458 WIN to kill anything needing killing.
The .458 WIN beats all.
Just a little handicapping with homemade bullets to spice things up now and then is delicious.

.458 Winchester Magnum Perfection
In maxima potentia parvum spatium.
Id venit et vicit omnis.

Bob's new bear load herewith,
we are always looking for such good load data for the .458 WIN, for THE MISSION:



His comments on the shooting, not bad for such an old guy, a tough old guy:

quote:

My thinking was to duplicate (or come close to) the 75 grs RL-15 load under the 405 Rem at 2085 fps as "my bear load". I planned on using 73 grs of H4895. Old lots of H4895 would have accomplished that. However, at the last few minutes I decided to try 74 grs H4895 (an "inspiration" moment), thinking it might give better accuracy.

The RL-15 load was sighted +1.31" at 50 yds. That would have been about +2.00 at 100 yds, though I never checked that.

Was I ever surprised when I pulled the trigger on the first 74 gr load under the 405 gr Rem: It went about 200 fps faster and shot completely over the target at 100! Though, it hit the backboard a few inches over the target, so I adjusted the crosshairs to that hole and fired my second shot -- it went dead on at center-hold.

I had loaded 5, so the next four were aimed dead-center zero. The target is self explanatory -- the one I called "pull" is out of the group at 100 yds. The other three went .57" c to c.

Average for the 5 was 2283 fps. Recoil wasn't bad at all. I'm gonna leave it at that. It will be my "bear load".

The little hole top left was a stray .22 LR. There was a gusty crosswind that blew that one onto the .458 target.

IIRC, Bob crimped on the bottom cannelure of the Remington .458"/ 405-grainer (Lee Factory Crimp die) for COL of 3.250".

Ballistics of Bob's load are better than the commercially loaded 400-gr TSX by Buffalo Bore, which had a custom run of those bullets,
still unavailable to the masses.

Remember to bug Barnes:

email @barnesbullets.com
customerservice@barnesbullets.com
http://www.barnesbullets.com
(435) 856-1000
(800) 574-9200

.458 Winchester Magnum Perfection
In maxima potentia parvum spatium.
Id venit et vicit omnis.

Drat ! I forgot that Barnes is closed Friday through Sunday,
so I flubbed the reminder.
Never fear, such a reminder is good support for THE MISSION.
It will be repeated frequently.

Come Monday:
Remember to call AND email Barnes.
Tell them you want the .458/ 400-grain TSX to be released to the public.
Everybody and his brother with a .458-caliber rifle of any kind wants it.
We know it exists and is being sold only to a boutique ammo loader.

Barnes Bullets
Business hours: 7:30 AM to 5 PM Rocky Mountain Standard Time
Closed: Friday through Sunday

Internet:

email @barnesbullets.com
customerservice@barnesbullets.com
http://www.barnesbullets.com

Telephone:

(435) 856-1000
(800) 574-9200


.458 Winchester Magnum Perfection
In maxima potentia parvum spatium.
Id venit et vicit omnis.

Bob's 100-yard 3-shot group with 405-gr Remington FNSN (at 2283 fps MV and 3.250" COL) is 0.57" on centers.
That is 0.54 MOA.
Elmer always said the .458 Winchester Magnum was ACCURATE.
Bob is too, even if he is a Canadian.
If I ever had to flee the anarchy in the USA I would head to Canada,
unless Alaska secedes.
That would be one better than leaving California, Illinois, New York, New Jersey, Washington, Oregon, Colonrado, etc., to move to Idaho.
There are already way too many Californians in Idaho.

Sample email to Barnes Bullets:

email@barnesbullets.com

customerservice@barnesbullets.com

Subject: 400-grain, .458-caliber TSX

Dear Sirs and Madams,

Regarding the 400-grain, .458-caliber TSX:
You are making this bullet for Buffalo Bore, a commercial ammunition loader.
What would it take for you to start selling it to the public ?
Must an internet forum get a group buy together ?
What quantity would be required ?
Could this be the alternative to adding it to your regular line of .458-caliber TSX bullets ?
The 400-gr, .458-caliber TSX has never been offered to the public.
Please do so, and good will to you, many thanks in advance.

Sincerely,

YOUR JOHN HANCOCK HERE


.458 Winchester Magnum Perfection
In maxima potentia parvum spatium.
Id venit et vicit omnis.

I certainly miss the Remington 405 soft points. They shot so well...

Okay RIP, was thumbing through this thread last night after a good cardio workout, went and grabbed my old Browning Safari 458 out of the safe, double gallon freezer bag of ammo contains 500gr Partitions, 450gr BBW #13 solids, and 450gr TXS's plugged into some nickel cases.

I'll chrono and shoot the old Boomer after while checking zero on the scope and iron barrel sights, then send you a few pics.

Doing my small part to stay focused on "The Mission!" ; ]

quote:

Originally posted by The Maz:
I certainly miss the Remington 405 soft points. They shot so well...

Try the 400 grain Speer. I reckon they are better. Super thin jackets.

https://www.speer.com/bullets/..._bullet/19-2479.html

I found that the 400 gr Barnes SP shoot very well but have not tried them on games yet

I think the 400-gr speer is not as tough as the Remington 405-grainer.
The Barnes 400-gr "Original" is mighty soft too.

Jerry,
6 images are incoming.

Buy a donkey to all for THE MISSION.

.458 Winchester Magnum Perfection
In maxima potentia parvum spatium.
Id venit et vicit omnis.

quote:

Originally posted by jerry mcdonald:
Okay RIP, was thumbing through this thread last night after a good cardio workout, went and grabbed my old Browning Safari 458 out of the safe, double gallon freezer bag of ammo contains 500gr Partitions, 450gr BBW #13 solids, and 450gr TXS's plugged into some nickel cases.

I'll chrono and shoot the old Boomer after while checking zero on the scope and iron barrel sights, then send you a few pics.

Doing my small part to stay focused on "The Mission!" ; ]

Pictures moved to Jerry's description below.

.458 Winchester Magnum Perfection
In maxima potentia parvum spatium.
Id venit et vicit omnis.

quote:

Originally posted by RIP:

I think the 400-gr speer is not as tough as the Remington 405-grainer.

[/b]

It never was Ron.

For the me the 400 grain Speer was not only a better bomb than the Remington 405 grain but also more accurate. Although for practical purposes the accuracy of both could be considered the same.

Speer Reloading Manual #13, 1998 (24" barrel):



Speer seems to have quit the .458/ 500-grainers altogether. The tungsten-cored African Grand Slam got so expensive they could not sell enough of them to keep it alive.
They still make a tough 350-grainer and soft 400-grainer.

The Speer 400-grainer is best reserved for varmints when fired at higher velocity,
like Mike's Kangaroo loads.
Meant primarily for big game use in lever actions and Trapdoors, up to 1800 fps MV is about right.
Dig Speer's "punkin roller" load at 1445 fps from 24" barrel below (15th edition of 2018):





I would rather shoot my 407-gr "Blue Bullet" at about 2150 fps,
and a 570-gr "Blue Bullet" at about 1300 fps,
if it works for double-bullet regulation.
That will take care of both varmints and big game.

A LongCOL loaded .458 WIN+P with 400-grain monometal copper at +2600 fps is very cool,
and very possible if loaded to .458 Lott pressure.
Double-bullet regulate that one with whatever you like.

.458 Winchester Magnum Perfection
In maxima potentia parvum spatium.
Id venit et vicit omnis.

RIP, thank you Sir for posting the pics, perusing this thread again, reading about all the 'long' COL's with the 458WM, as well as higher velocities with the newer [unobtainum in these parts] powders, along with remembering what Michael458 said about the 450gr BBW solids in the 458 WM, I had to get my old 458 out and have a refresher with it.

Pic 1, 450gr BBW#13 solid and 500gr Partition.

Pic 2, Velocity reading for 450gr solid.

Pic, 3, should be pic 4, at the bench about to move the box to 50 yards and have at it with the barrel sights.

Pic 4, Velocity of 500gr Partitions, more on that load in a minute.

Pic 5, two shots at 50 yards, minute of Buffalo Brain any day.

Pic 6, two rounds on right at 100 yards, one round on left after removing, then reinstalling scope to check return to zero, 500gr Partitions.

I love this old rifle, cant seat long, or get any of the AA powders here, my old load under both bullets is with H-335 powder, I've read here and had previously heard compressing that powder can lead to problems, so, on a 105 degree day a couple summers ago, I took rifle and a handful of ammo outside on the concrete slab and let em cook for three hours, turned the rifle over and let it cook another hour, grabbed the chrono and fired three, av. velocity read 2155 fps, yesterday mornings temp at firing was around 81 degrees, not bad at all, I've thought about paying hazmat on some AA powders and trying them in my 458, but, having near 200 rounds loaded with the 500gr Partitions and H-335, I may have to make due as is.

Still enjoy reading what you're doing with the long action 458.

I love seeing those CEBs!

boom stick, from what I've read about them, those 450's at 2300 fps may be a very good 'do it all load' in the 458WM.

Getting it correct, for THE MISSION:

quote:

Originally posted by jerry mcdonald:
RIP, thank you Sir for posting the pics, perusing this thread again, reading about all the 'long' COL's with the 458WM, as well as higher velocities with the newer [unobtainum in these parts] powders, along with remembering what Michael458 said about the 450gr BBW solids in the 458 WM, I had to get my old 458 out and have a refresher with it.

Pic 1, 450gr BBW#13 solid and 500gr Partition.
One:


Pic 2, Velocity reading for 450gr solid.
Two:


Pic 4, Velocity of 500gr Partitions, more on that load in a minute.
Four:


Pic, 3, should be pic 4, at the bench about to move the box to 50 yards and have at it with the barrel sights.
Three:


Pic 5, two shots at 50 yards, minute of Buffalo Brain any day.
Five:


Pic 6, two rounds on right at 100 yards, one round on left after removing, then reinstalling scope to check return to zero, 500gr Partitions.
Six:


I love this old rifle, cant seat long, or get any of the AA powders here, my old load under both bullets is with H-335 powder, I've read here and had previously heard compressing that powder can lead to problems, so, on a 105 degree day a couple summers ago, I took rifle and a handful of ammo outside on the concrete slab and let em cook for three hours, turned the rifle over and let it cook another hour, grabbed the chrono and fired three, av. velocity read 2155 fps, yesterday mornings temp at firing was around 81 degrees, not bad at all, I've thought about paying hazmat on some AA powders and trying them in my 458, but, having near 200 rounds loaded with the 500gr Partitions and H-335, I may have to make due as is.

Still enjoy reading what you're doing with the long action 458.

quote:

Originally posted by jerry mcdonald:
boom stick, from what I've read about them, those 450's at 2300 fps may be a very good 'do it all load' in the 458WM.

Yep.
SAAMI loads to +2300 fps with any 450-grainers, no problemo.
You do not really need to load them to +2450 fps and +6000 ft-lbs KE,
but you certainly may do so by loading them long and to less pressure than in the SAAMI .458 Lott if it could do the same. THROAT.
That works with the excellent band/cannelure configuration of the Barnes monometal bullets.

The CEB 450-grain Safari Solid used in the .458 WIN+P, due to its peculiar band paucity and spacing, is best limited to COL range of 3.340" to 3.360".
But pressure may certainly be increased to .458 Lott levels if desired, or not.

To use this CEB at 3.340" COL in the .458 WIN,
trim brass to 2.485".
Leave brass at 2.505" (maximum for .458 WIN+P) and COL is 3.360", seated as shown:




Better band structure of the now unobtainable Barnes Banded .458/ 450-gr brass FN solid:






Submaximal .458 WIN+P loads: 2400 fps for 450-grainers, 2600 fps for 400-grainer.
Starting loads: 2300 fps for 450-grainers, 2400 fps for 400-grainers (filler not required, but may be used to eliminate "powder shake.")

.458 Winchester Magnum Perfection
In maxima potentia parvum spatium.
Id venit et vicit omnis.

RIP, Thanks for the lineup correction and further 458 Win +P research and development legwork ; ]

You have me thinking, I happen to have a Rube Goldberg M-70 in 375 H&H, the action is from a G series model 70 in 7mm STW I bought in the early 90's, torched the throat on that rifle, bought a stainless 375 barrel and had my 'Smith install it.
The barreled action sat for years on a safe top, well, one day a beautiful walnut stock with 14" LOP came along, I bought it, then appeared some beautiful stainless bottom metal, grabbed that too, took all the parts and pieces to my 'Smith, he bedded the tang, action and full length of the barrel channel, also bedded and fit bottom metal snug as a bug in a rug, had him install a set of engraved cross bolts too.

The rifle is beautiful with matte blue action, stainless barrel and bottom with the walnut stock, it's a hell of a shooter too.

BUT, and I mean a big BUT!......what about making up some 458 WM dummy rounds with the big 500gr Woodleigh round nosed Weldcores at a full 3.600 inch, sending them and the barreled action to JES for a 458 Win Mag re-bore?

That should make a hellbender of a 458 +P+ Win Mag, i know the rifle [stock] will handle the increased recoil, plus, already having a cool old 1952 year model pre-64 375 H&H, I may not even miss ole Rube in 375 guise, thoughts please.

Big Mac, a 375 is just a BB gun in your arsenal of big-bores. Go for it!

Jerry,

First, I shall adopt the "+P+" nomenclature you have suggested.
Henceforth, if a .458 Winchester Magnum load exceeds SAAMI MAP of 60,000 psi, yet is </= 3.340" COL, then it is a ".458 WIN+P" load.
If the load is greater than 3.340" in COL, then it is a ".458 WIN+P+" load, whatever the pressure is, up to 62,500 psi MAP.

Secondly, of course I think your idea for a "hellbender of a 458 +P+ Win Mag" is simply brilliant, marvelous, plumb fantastical.

If it comes to pass, that would get a lot of mileage here at THE MISSION if you will allow a buy a donkey in advance.

In fact, I have a stainless M70 Classic .375 H&H that was re-chambered to .375 Wby that is also super accurate.
A re-bore of that to .458 WIN+P+ is the only thing I would ever dream of doing to it for improvement.
That factory .375 H&H barrel is hefty
(rifle is 8 lbs 11 oz as shown below when scope removed, no ammo),
needs a bigger bore hole to lighten it:



Here is Marcella McGowen-Winchester, my ultimate weight reducer, 1 lb and 6 oz lighter than a factory M70 Super Grade in .458 Winchester Magnum,
a re-barreled, re-stocked, factory M70 Classic .416 Rem. Mag.:







A few ounces heavier, all-stainless M70 Classic would be really nice.

Starting load for Marcella (23") was 65 grains of AA-2230 with 543-grain FNGC cast bullet at 3.340" COL for 2024 fps (5-yard chronograph).
A mere SAAMI .458 Winchester Magnum load by MAP and COL, I am sure, accurate too.

Same bullet with 75 grains of AA-2460 and 3.600" COL from a 25" Shilen barrel gave MV of 2258 fps (2248 fps 5-yard chronograph).
Accurate again.
That might be a .458 WIN+P+ load,
maybe pressure is a little over 60,000 psi ?



The magazine box of my M70 (Marcella) is 3.630" long inside.
The .458 Lott exceeds 3.600" COL if bullet is seated longer than shown above, for crimping in next groove.
And the .461" diameter front band won't even chamber in a SAAMI .458 Lott throat.
Any cast bullet seems to shoot very well in a .458 Winchester Magnum if bullet diameter is .461".
That goes for any barrels with either .458" groove diameter or .459" groove diameter.

I must confess that at 3.600" COL and .461" diameter, that 543-gr SAECO #020 is just about bumping against the leade.
Sizing the front band down to .459" would alleviate this.
I have just learned about nose sizing from JFE.

.458 WIN-V 3.4"/.3.6"/.3.8": These designations may still be used to refer to rifle configuration of .458 Winchester Magnums.

.458 WIN, .458 WIN+P, and .458 WIN+P+: Ammunition loading specifications for the .458 Winchester Magnum and its wildcat.

.458 Winchester Magnum Perfection
In maxima potentia parvum spatium.
Id venit et vicit omnis.

LOL, Thanks for the vote of confidence Biebs, and Yessir, 22 Hornet to 8 Bore, 375's would be about right middle bore in that lineup ; ]

You're most welcome on the nomenclature adoption RIP, papers already signed.

UH-OH, IIRC the 375 WBY shoulder may be too fat to cleanup with a .450 bore, you may, god forbid have to wildcat that one to a straight 2.8" case .500/509........502/.510 shoulder pounding beast of a 50 cal.

Marcella is quite the svelte little lass, agreed on the classic barrels, WAY to damn fat, a bigger hole would indeed help, glad my old pre-64 375 isn't so piggish, i'll send you some pics of Rube after a bit if you'd like to see the potential conversion specimen.

Good work on COL comparisons too, and damn nice neck down/step down crimping, those bullets aren't going anywhere till the p charge kicks em in the butt.

My conversion idea for 458 Win Mag+P+ is both 450gr TSX and BBW #13 solids at an accurate and functional 2500 fps, the solids at that speed should blow through anything with the TXS's working from 5 to a long 300 yards if need be, pretty damn versatile setup there.

Just thinking out loud here:

450gr TXS at 2500 fps
+3 at 100
0 at 200
-9 or 10 at 300

Should still be packing near 1900 fps at 300 yards, yep, that'll bring the tough love from three football fields away. ; ]

Jerry,

Dang if you ain't right about the .375 Weatherby not being cleanable by a .458 WIN reamer.
The .375 WBY chamber diameter is 0.496" at 2.436" length from base/breech face.

That is a relief for me in that the .375 Wby barrel can be screwed off and a .458 WIN McGowen #5 sporter contour can be screwed on.
I have never had a rebore done, and I still do not need one.
That would be the ultimate slow-switch-barrel for me.
.375 WBY & .458 WIN-V-3.6" capable of firing .458 WIN+P+.
It is going on the schedule,
right after the .500 Jeffery Match Cast Shooter.
My excuse for doing that is to keep me from having a 50-140 Sharps done.

Please do send any pictures you might have of "Rube" for THE MISSION,
I will get to it whenever chores get done.

.458 Winchester Magnum Perfection
In maxima potentia parvum spatium.
Id venit et vicit omnis.

Rube or Ruby ?
Pretty rifle. Barrel is about like a factory M70 Classic .375 H&H from Connecticut, plenty heavy enough for rebore to .458:











Dressed too fine for a truck gun, but somehow reminds me of a song about a redneck girl who likes to cruise in Daddy's pickup truck ...

https://www.youtube.com/watch?v=kSOqsfaaEk4


.458 Winchester Magnum Perfection
In maxima potentia parvum spatium.
Id venit et vicit omnis.