Home Forums Hunting & Shooting Express Rifles and Big Bores Only The great 458 Winchester. Everyone should own one at least once

I just don't see the 458 Win doing anything better than my 416 Rem can.

Three cheers for EdM for the side table display.
Hip-hip-hooray.
I once rebarreled a .416 RemMag to .458 WinMag.
She was a Winner.
EdM's rifle would be a lot more interesting if it was a .458 Winchester Magnum
that shoots 404-gr Shock Hammers of about 0.419 G1 BC at faster MV than a .416/400-grainer can do
from a .416 RemMag at 65,000 psi SAAMI MAP.
Hence the .458 WM+ housed in the M70 Long Action would have a flatter trajectory and greater impact at all ranges.
It could certainly beat the .416 RemMag at lesser pressure, whatever MV is desired.
The standard SAAMI .458 WinMag of 3.340" COL pushes 400-grainers to +2400 fps MV at 60,000 psi MAP.
Assume 24" barrels all around.

Jacketed and monometal bullet weights from 250 grains to 600 grains: .458 Win
Cast bullet versatility outstanding, even paper-patched and BP, with even greater weight range: .458 Win
Subsonic to near Mach 3: .458 Win
Greater powder variety versatility: .458 Win

Back to Square Table business now, at the center of the great room.

Order in the great room please.

I make a motion to accept a new BENCHMARK benchmark as a Square Table standard for the King of Cartridges.

The WOODLEIGH BULLETS LOADING MANUAL has tabulated BENCHMARK 2 (ADI) = BENCHMARK (Hodgdon) loads
for the SAAMI .458 Winchester Magnum.
First the powder tables to show equivalence of the ADI and Hodgdon powders,
always showing same loads and results for these two powders in the Woodleigh Bullets load data to follow:







All the load data benchmarks are in the Woodleigh data for 400-grainer to 550-grainer.
There is even a separate tabulation aimed at regulation loads for the .458 WinMag double rifles circa 1970 to 1990,
before the flanged cartridges revived, short lived as it may have been.

Consider this load data to be SAAMI satisfying for the .458 Winchester Magnum,
this is correctomundo IMHO for
3.340" Max COL
60,000 psi MAP
24" rifle barrel length
1:14" twist
0.458" to 0.459" groove diameter
Hornady, W-W Super, or Remington brass of 94 to 95 grains water gross,
and Large Rifle Magnum Primer of the F215/WLRM/CCI250 types.

Here is the double rifle regulation load data for 26" barrels and 480-grain bullets:



And a further illustration of the short-nosed 480-grain bullet suitable for the true .450 NE with no throat,
also works in the .458 Lott shortie-tightie throat with brass too long for a 3.6" magbox,
whereas the longer-nosed bullet is desirable in the .458 WinMag:

The Woodleigh bullets offered to handloader in the 2014 edition manual:

To compress powder or not to compress powder ?
That is the question.

Do I hear a second to the motion to accept the WOODLEIGH BULLETS LOADING MANUAL, 2014 edition,
as the BENCHMARK benchmark for .458 Winchester Magnum,
with bullets from 400 grains to 550 grains ?

Reference to that data will be used for comparison of any rifle shooting same BENCHMARK load
without regard to ambient temperature.
By extension, other bullet makes of same weight may be considered for effects on MV.
Ditto for effects of differing seating depths.
Ditto the effects of shorter and longer barrels.
It is a place to hang the thinking caps of the Knights of the Square Table.

I'll second you RC!

Man, you definitely have that old 458 sorted out. Really a great thread.

I move that all data, experimentation and JB welding concerning the magnificent 458WM submitted by RifleCrank aka RIP, be considered “The Benchmark” on said topics until gasoline is $0.99 a gallon at Walmart at which time the floor will again be open for consideration.
F01

With a second from Sir Scotty
and a third (and more) from Sir Dennis,
a telepathic vote has been taken.
The aye's have it.

Resolved:
Woodleigh BENCHMARK (Hodgdon) aka BENCHMARK 2 (ADI) loading data
is henceforth considered to be the standard "Benchmark Load" for comparison of rifles
conforming to SAAMI .458 Winchester Magnum homologation standards.
This may be done without regard to piddly differences in ambient temperature.

This will assume use of Woodleigh Bullets cannelures for actual COL of less than or equal to 3.340",
60,000 psi MAP
24" rifle barrel length
1:14" twist
0.458" to 0.459" groove diameter
Hornady, W-W Super, or Remington brass of 94 to 95 grains water gross,
and Large Rifle Magnum Primer of the F215/WLRM/CCI250 types.

The Benchmark Load will be the baseline for the individual rifle,
indicating its relative speediness.
Differing load characteristics, non-SAAMI chamber, or rifling variations may then be interpreted,
thus facilitating any 'splaining to be done ...
like how the .458 WM+ so thoroughly trounces the .416 RemMag and .458 Lott.

At least it is a ".45-caliber" rifle, thus showing some degree of intelligence in Ray Livingston.



But dang if he didn't go tacticool all over his .460 S&W lever action !

The .460 S&W with 1.8" case (lengthened .454 Casull) has a MAP of 65,000 psi.



The milder mannered .450 Bushmaster has a fatter case head, shorter 1.7" case
(shortened .284 Winchester reprobated),
and a MAP of 38,500 psi SAAMI.
It is much loved due to working in the ARs and bolt actions that Bubba can afford
without a sponsorship from Big Horn Armory.



Please bear with me. We are about to get to something interesting.

Barrel shortening effects from 27" to 13" on six different cartridges, including the .45-70 Gov't. !

https://matchgrademachine.com/velocity-testing-thompson-center-barrels/#magnum

Home on the range, not-so-encouraging words were heard about the viciousness of the .460 S&W:

Lovefest for the .450 BM:

Finally a ho-hum on the .45-70 Gov't.,
at least they mention it as a favorite chambering for their customers:




I think Ray Livingston would do better with a .45-70 Govt. and all kinds of different rifle bullets
available for it, if he is a handloader.
He would probably not get a sponsorship for carrying a Winchester 1886 with a .458 WinMag throat
to handle up to 2.8" COL.
Maybe Ruger-Marlin will sign him up and he can tacticool one of those in .45-70 LT.
Either of those would be able to kill cow elk and coyote at close range,
like he has been doing with his .460 S&W M90.
I think he has a the 22" barreled one and he has been using a suppressor that adds about 8" or more to that.
Like a 34"-barreled Sharps for overall length.
Mountain Man style tacticool.

The velocity changes on the .45-70 Gov't. are interesting.

from 27" to 13": -267 fps/14" = -19 fps per inch for that huge range.

from 27" to 20": -75 fps/7" = -13 fps per inch

from 20" to 13": -147 fps/7" = -21 fps per inch

from 24" to 22": -4 fps/2" = -2 fps per inch

from 24" to 23": +1 fps/1" = +1 fps per inch of barrel shortening.

That is with 405-gr Remington FNSP and H4198.
The .458 Winchester Magnum might be very similar to that.
Maybe just shift the curve to the left by an inch to allow another inch of barrel
for burning of the bigger charge of powder.
28" to 14" for the .458 WinMag Encore, heh-heh-heh.

I did read the MGM article, but I didn't see how many shots were fired at each length. Did they only fire one shot, or did they fire a number of shots to improve the statistical average? Three to five shots would be nice, and ten per cut would be a fantastic number to give good data.

As I re-read my post it may come across as smart-ass or snarky, and that is not my intention. I have only posted a few times, but I have read every page. I find this site a true wealth of ballistic information for the 458 Win Mag, along with other bigger bores.

Sir Ron,

BENCHMARK or BENCHMARK 2 (BM2) as it's known in Australia is all l use in the mighty .458 now...

And in regards to the velocity the excellent Woodleigh manual state, here's what l got from the 24" barrel from my Zastava loaded to 3.340"

550gn Woodleigh and 73gns reached 2080fps which was only 30fps under what the manual stated
And
450gn Hydro and 75gns reached 2320fps which was 40fps above what the manual states.
(I now load 73gns - same as my 550gn load which gets me spot on 2280fps)

BENCHMARK is a truly wonderful powder for the king of cartridges.

Russ

The Old Virginian,
You make a good point.
I could not tell either, how many shots per inch.
A local custom handloader did the loading and shooting for MGM.
MGM did the barrel cutting and cleaning.
With that division of labor, surely they did at least 3-shot groups.

They did say that there was some vertical stringing and unexplained velocity variation in some of the GROUPS shot
with the .460 S&W.

This suggests 3-shot or more-shots than that per load, per inch of barrel cuts.

One-shot data points would be bogus indeed.
10-shot groups would have smoothed those "curves" out nicely.

Pick your Sir Name and pull up a chair at the Square Table, please.