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

[ldmay375]

The CEB Safari Solid #13, 325 grain .458 is poster child for design and construction.
I think there is a chap on this forum that give the field results of this bullet, on an elephant out of his buddy's 450 Nitro. Amazing bullet. Who the heck would have thought a 325 grain .458 bullet could perform as such ?? Though the tests certainly indicated the probable outcome.

 

[Slyfox72114]

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.

Riflecrank
Sorry I missed your response.
I just bought this rifle at a local auction. The auctioneer called the gun collector and he said his father or grandfather bought this from PO Ackley and it’s a 458 Ackley improved this past weekend. I took the stock off thinking I’d see some markings and there’s zero markings on the barrel that indicate what it is , so that has me rightfully concerned to try to put a bullet off in it based on what this gentleman said your advice is much appreciated. Thank you.

 

[Slyfox72114]

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.

Thanks Rifle,
Here are a few measurements if you don’t mind looking?

The magazine block is 3 3/4 inches

I’m calling that the receiver is 3 1/2 inches

The 06 and a 300 win mag sitting on the bolt both show room left over for the 450 or 458.

 

[Riflecrank]

Hold up !
I just saw your images of the bolt face that looks too big for an H&H belted case.
Looks like a .416 Rigby or .460 Weatherby size bolt face.
Do not fire .458 Lott ammo in that rifle until you get a chamber cast.
Slug your barrel also to check the rifling groove diameter, easy if the number of grooves is even (2, 4, 6, 8, etc.)
but hard to interpret accurately if the number of grooves is odd (3,5,7, 9, etc.).

 

[Slyfox72114]

Hold up !
I just saw your images of the bolt face that looks too big for an H&H belted case.
Looks like a .416 Rigby or .460 Weatherby size bolt face.
Do not fire .458 Lott ammo in that rifle until you get a chamber cast.
Slug your barrel also to check the rifling groove diameter, easy if the number of grooves is even (2, 4, 6, 8, etc.)
but hard to interpret accurately if the number of grooves is odd (3,5,7, 9, etc.).

Stay tuned my wife has some Cerrosafe ordered and I will pour a cast of the chamber this weekend. This is exciting because I didn’t know what Cerrosafe was until 30 minutes ago!
It’s great a little bit of knowledge from others goes a long way…

 

[Riflecrank]

Slyfox72114,
That is mighty sly of you for kaboom prevention.

 

[Riflecrank]

Michael458,
No apologies for wandering off topic.
It is all on topic and welcome words if coming from you.
Agree on twist, 1:12" for .416 Dakota I had built on an M70 RUM action.
My .500 wildcats have used 1:12" X2 rifles.
My .510 wildcats have used 1:10" X 3 rifles, 1:12" X 2 rifles, 1:20" X2 rifles, and a 1:9" X1 rifle.
The slow twists of 1:20" were on my ".500 Jeffery Match" (that is the CIP spec for .500 Jeffery) and on
my ".50-70 Little Bighorn."
Both meant primarily for heavy cast bullet fun, with the .500 Jeffery Match being fully equivalent to a .50-140 Sharps for BPCR "match" work, heh-heh-heh.

1:12" was also used on .35 Whelen, .35 Brown Whelen and (Lord help me !) my 5-different .395 Wildcats in 6 different rifles.

1:12" even works great on a .300 WinMag with 185-gr Berger VLD Match Grade Hunting bullets in a custom rifle of a friend that gets them up to 3160 fps MV from a 24" barrel !

For .458 WinMag 1:14" is great.
So is 1:10" which I have from Pac-Nor on a .458 WM+ and a .458 B&M+.
Any velocity or pressure changes with twist in going from 1:14" to 1:10" are nil.
The .458 B&M is a fantastic cartridge, my favorite of your B&M line.

I think a faster twist also helps with the transition from air to animal tissue or other denser media,
to keep the FN solid on course even if it does not impact the surface of the target perfectly normal/perpendicular.

You can even get by with cast bullets in 1:14" twist at usual velocities in a .458 WinMag.
1:10" is a bit too fast unless you are using really heavy ones subsonic, like 600 to 750-grainers.

 

[Riflecrank]

Back in the old days before I knew of the McCourry Institute of Ballistics (MIB) headed by Doctor McCourry (Doc M) in South Carolina it was rough.
I was trying to interrogate bullets myself in what I called the Iron WaterBoard Buffalo.
I quit the torture soon as I had access to MIB data.
I will claim to have suggested the "witness cards" to Doc M by using the cardstock found in storage bags and boxes of my comic book collection.
He immediately improved on this with the idea of laminating some larger cardstock to fit his bullet trap cross-section.

Frozen waterdrops one winter night after testing a custom .500 Jeffery bullet from a forum member with handle "Jeffery_in_Denmark." He mailed the bullets from Denmark.

Penetration scores:
GSC 340-gr/.395 Copper FN: 7.0-
S&H 330-gr/.395 Brass FN: 8.0+
Out of a possible 10.0

I never got around to trying a .50 BMG or a .416 Barrett with proper brass FN solids at maximum velocities from 32" barrels.

Jeffery_in_Denmark's 540-grain/.510-caliber Copper Monometal Cup Point scored only 49" or 5.0-. Impact velocity was about 2400 fps from my .500 A-Square with 1:10" twist.
Impressive for an "expanding solid."
See 5 missing buckets in nighttime photo of IWBB above.

 

[Riflecrank]

Just to continue the hijack, here is how Mike Brady, originator of North Fork Bullets, tested bullets,
with blocks of bookbinder glue that could be melted and moulded for re-use after he blew them up inside a long, steel drum with doors on the side:

Nowadays, to me, only .458-caliber bullet tests are interesting, just like an accurate .458 WinMag rifle.
There, back on topic.