IIRC, most of the 45-caliber muzzle-loaders have a .450" bore-diameter and groove diameters of .460"-.470", with varying patch thicknesses,
and .440"-diameter balls.
Patch as sabot.

Sounds like the 45-cal muzzle-loader sabots would be a perfect fit in the .450"-bore/.458"-groove.
Not loose. Not tight. Hopefully matching the bore perfectly.
And designed to accept .355"-357" diameter bullets,
the .358"-diameter should be good to try.
Any error there is only .001" on the tight-fit side, not bad.
The goal is to get a lighter, faster, higher BC load that is accurate.
A worthwhile challenge.

I tried the old .30-06/.22-caliber factory, sabot loads, decades ago, and was not impressed with the accuracy,
though the MV was close to 4000 fps.

Accuracy is paramount. Definitely a worthy experiment: .358-sabot/.458 Win Mag.

But, if that is not satisfactory in the accuracy department, you might be better off for caribou using that GS Custom .458/400-grain HV at +2400 fps.

Phil Shoemaker says the old Barnes X-Cannelured .458/400-grainers penetrated big bears as well as anything. Sufficient!

It would probably be a perfect cape-buffalo bullet too.
That is my idea of the .458 WinMag all-around load for near or far, big or small game.
Sight appropriately and know the trajectory for one load.
Use any solid you like that shoots close enough at close range.

Speaking of which:
Reviewing the thread, stradling clocked the old Hornady Heavy Magnum loads that claimed 2260 fps with 500-grainers in 24" barrels?
He got 2150-fps-ish in 22"-ish barrels.
Pretty darn good!

No one has added a clocking of the current Hornady Superformance 500-grain DGS (factory load) to this thread that I could find.
Though lots of excellent handload data from many here.
That can save some money.
Lessee, 20 shots for $93.27 (after tax) at the local emporium: $4.66 per cartridge.
I'll save some of those as a backup to the 400-grain loads.
Just for fun, those will be scope zeroed at 25 yards, and will see where the 400-grainers land after that.
Starting with the re-trial of slowed down cast bullets.

Rip
.

A. The .458 WinMag at <3.4" COL is compared to the .458 Lott at 3.6" COL.
If both are loaded to same pressure,
the .458 Lott has only a 60 fps MV advantage.

B. Load that .458 WinMag to 3.6" COL, and the .458 Lott has no advantage,
plus the .458 WinMag is easier to fit in a 3.6" box magazine, by a wee bit, and it feeds better.

C. Load that .458 WinMag to 3.8" COL, and it beats the 3.6"-length .458 Lott,
plus the .458 WinMag is easier to fit in a box magazine, by a wee bit, and it feeds better.

Plenty of Missouri Mule work for me and the .458 WinMag, soon as I put some other stock out to pasture.


Rip
.

This thread has been both terrifically educational, and inspirational. As a result, I now own a 458 WM. It is a build from a gunsmith student using a MRC 1999 action and a Shilen barrel. Apparently the novice builder felt a 20 inch barrel, in a sub 8 pound gun of this caliber was the way to go. I am too ignorant to formulate any argument to the contrary. I took delivery and tested it with some rounds I loaded up using 405 grain hard cast with 70 grains of Varget. A more pleasant experience than I expected. Actually quite fun. Accuracy, while not the focus of today's venture, seemed promising.
So, can anyone suggest a load using Varget and 350 grain TSX bullets? I have acquired some of each and would like to combine them into something functional and versatile.
On a side note, how is it that so many consider the 375 a suitable DG caliber but will argue the merits of the decidedly more powerful 458 WM in the same role?

quote:

Originally posted by mlazarus:
This thread has been both terrifically educational, and inspirational. As a result, I now own a 458 WM. It is a build from a gunsmith student using a MRC 1999 action and a Shilen barrel. Apparently the novice builder felt a 20 inch barrel, in a sub 8 pound gun of this caliber was the way to go. I am too ignorant to formulate any argument to the contrary. I took delivery and tested it with some rounds I loaded up using 405 grain hard cast with 70 grains of Varget. A more pleasant experience than I expected. Actually quite fun. Accuracy, while not the focus of today's venture, seemed promising.
So, can anyone suggest a load using Varget and 350 grain TSX bullets? I have acquired some of each and would like to combine them into something functional and versatile.
On a side note, how is it that so many consider the 375 a suitable DG caliber but will argue the merits of the decidedly more powerful 458 WM in the same role?

mlazarus,

cant wait the answer as i was waiting for the same combo of varget and barnes bullet.

Wish I could help with Varget and the 350-grain TSX.
Maybe CTF has tried it?

I suspect Varget will yield an accurate and moderate velocity load.

Hodgdon 2017 Annual Manual lists Varget with 400gr Swift A-Frame softpoint.
24" barrel, 1:14" twist
CCI-250 primer
Case: Winchester, 2.490" trim-to-length
Bullet: 400 GR. SFT SP Dia.: .458"
COL 3.220"
VARGET 74.0 grains >>> 2246 fps <<< 34,500 CUP (starting load)
VARGET 77.0 grains (compressed) >>> 2310 fps <<< 38,800 CUP (maximum load listed)

I would start at 70.0 grains of VARGET with the 350-grain TSX and work up, using whatever COL suits you and your rifle.

If you have a bunch of Varget, you should get some nice shooting in with that.

With a medium rate powder like Varget, it will be hard to cause any mischief with the light bullets like 350-grainers.

About 30 years ago I used IMR-4198 and the Hornady 350-grainer to get an easy and safe +2500 fps.
After too long an absence from the .458 WinMag, NOW I AM BACK!
Shacking up with the .458 WinMag again.
She's a good ol'gal.

I will be going with H322 and H4198 for higher velocity with the .458/350-gr TSX.

Bob Mitchell did this, and I believe it:

https://bigborefan.wordpress.c...8-winchester-magnum/

CZ 550 bolt action (25″ barrel)
Bullet: 350gr TSX
Powder: 80grs H4198
Case: Winchester
Primer: WLRM
MV = 2753 fps/5890 ft-lbs/137.65 ft-sec. momentum
PSI = 64,000 approx.
Zero = 250 yds for moose/ 100 yds for bear
Accuracy: MOA
COL: 3.45″

Rip
.

I've never gone that high a weight of 4198 with the 350s . since 2550 fps did Everything I ever needed it to Very well !! I stopped there and ran it lots @ 2500 fps . didn't notice any reduced killing ability.

I kinda loose my mind when some bone head flat out stated that a 350 gr X or TSX at 2500 fps would only be good for plains game from a 458. And yet the same person states the 375 300 gr is good for cape buffalo . At the same velocity.
If I was going cape buffalo hunting all I would want in my rifle is the 350 gr TSX@ 2500 + fps.
I would feel just as good with GSC HV in a similar weight and velocity. And for lion, either the 300 gr TSX@ 2700 fps of the 350/ 2500 fps load.

ManufacturerHodgdon
PowderH4198
Bullet Diameter.458"
C.O.L.3.105"
Starting Load
Grains67.0
Velocity (ft/s)2,426
Pressure44,700 CUP
Maximum Load
Grains72.0C
Velocity (ft/s)2,548
Pressure51,600 CUP
Bullet 350 gr Speer Hot Core.
This is a load I have shot a lot with this same bullet.

I DO NOT RECOMMEND THE 350 GR HORNADY in the 458 for anything more than target shooting. Terribly frangeable !!!!!!!!!

As to Varget and the 350 gr bullets. It would be very generally useful ! Prolly get around 2400-2450 fps with it. A 350 gr 458 bullet of good construction @ 2400 fps is pretty impressive !

mlazarus

quote:

varget and barnes bullet

quote:

I would feel just as good with GSC HV in a similar weight and velocity

GSC will be more than likly faster than the barnes so in the 20 inch tube may be worth the extra cost and work for that important once in a lifetime hunt

I shoot the cheap stuff --so not saying barnes is exactly cheap, it's not not even close

The 20 inch barrel will be slower but

you may get more velocity than you think

we do not currently have a 20 inch barrel to test

and I can not load for--- your rifle chamber--- but if you load up 10 in 1/2 grain increments and--- walk em up in to pressure --- you more than likly will be happy with what you have got in that gun

it is a mathematical certainty it will kill well ahead of a 375 hh no matter the velocity you stop at

you should expect to be surprised how flat and accurate it shoots

the recoil will be acceptable



getting your first 458 win mag is about as exciting as it gets



don't [next] go stupid on us and buy a $7,500 african safari at auction [for a $500 bid/ it can and has several times happened to unfortunate souls]

after you get good at running that nice little gun

you are going to love that little gal

no coming back from that tip over

welcome to the --James Watts 458-- world

if it were my gun I might drill a 1 inch hole in under the butt pad and fill it with hot lead adding about a pound to the running weight much more comfortable to shoot that way

don't need the merc recoil tube lead will do the trick

what we do ---in the custom million dollar each--- gun shop is drill 2 holes one in a oak block and the other one in the gun [can be tricky first time you drill out the back of a stock so ]

pore the hot lead in the wood block take it out and epoxy it in the back of the gun

pore a bar to insert in the forearm to end up with a well balanced rifle

and

wala ---you are heavy, hot, balanced, and confident

with your loaded up, short barrel carbine, murder machine

at exactly the weight that fits

what you want
what you like
what you can best perform with

after you do all that

you will never look back

squirrel gun -- moose gun -- bear gun -- elephant gun -- your all round-- go anywhere-- anytime-- kill anything gun

now you really do have a custom rifle

custom build
custom load
custom fit
custom weight

specific to and for you

what the hell is custom
if it's not your custom gun

anyway

the 458 watts short was not conceived to hang on the wall and pontificate over and about

thought up to go out and kill stuff with

quote:

On a side note, how is it that so many consider the 375 a suitable DG caliber but will argue the merits of the decidedly more powerful 458 WM in the same role?

I am not sure that those are the same people that you are grouping together.

In fact, I know a lot of people who look at the 375 as "legal" but not the best choice for someone on their own. So I am not really a .458 fan, nor a 375 fan, but they are legal. The 375 is a great antelope gun that can be used for buffalo if nothing better is available. The 458 is better for buffalo than the 375, but lacks trajectory for all-around antelope.

Scoped now, here is that "Longclaw" cast-bullet shooter, again:



It weighs 9 lbs 5 oz empty, scoped, with a Lyman 48 receiver sight base left in place.
The 3-leaf-express rear sight can be screwed off and replaced with a folding single-leaf rear sight.
That part is in the "Mauser Parts" box, on a shelf, in a messy room, along with the rest of the Lyman 48 sight.
Add 4 rounds of 500-grain .458 Win.Mag. ammo to that and it weighs 9 lbs 12 oz.



I had no trouble scrubbing the barrel clean of lead from the first misadventure with cast bullets.
Will chronograph that Hornady Superformance 500-grain DGS to zero the scope.



Then hopefully the Berry's Hard Cast 409-grain bullets will fly true at something like 1200 to 1600 fps.

"Squirrel season is coming."
(Salutation from GAME OF RIFLES saga.)
Rip
.

Note the "Storm Queen" scope covers on the little Leupold 2.5x20mm scope.
That scope suits that rifle perfectly.

We owe those "scope caps" to James Watts also.

He went to Harvey Anderson with an idea for waterproof scope covers in the late 1940's.
Harvey and James Watts made some.
James turned the idea over to Harvey and moved on.
Harvey turned that into a business. Those things still sell.

That is according to Cal Pappas' book, which is primarily a transcription of his interviews of James Watts.

Squirrel season is coming ... GOR
Rip
.

The Spruce King's barrel is a Shilen. And it's a fast barrel. I bet Mlazarus's barrel will be also. We can't really talk about the 458 without talking about underbarrel recoil lugs. I hope his has one. That has been The cause of many many split stocks and peddled barreled actions. That's how I got my first 458 in 85. It was a Sako that apparently was sold without an underbarrel recoil lug. What the guy I got it from told me was . All of them split their stocks. So Sako recalled them all and resold them as just barreled actions. Don't know if that's true , but that's what I was told. It had a 19" barrel . and a nice chunk of steel for the 2nd lug when I bought it for $640.00 iirc. In 1985 dollars. Selling firewood for $80.a cord. Split and delivered. I just had it up and shooting with an MPI Whetherby style fiberglass stock. As I remember I put a 3x magnum pachmier pad on it. With 72 gr of 3031 and a 500 gr Hornady I could feel the pad bottom out at peak recoil. And unless I had a real muckle on the foreend I would have to reach up and pull it down out of full recoil to cycle the action. . . I do Not like 3031 !!! Eratic velocities, pressure spikes, and other problems is about all I remember about it.

Ah---underbarrel recoil lugs.

McGowen will do an under-barrel lug cut into the barrel blank, with a balanced open sights island on the top. Exactly like CZ.

I had my 500 done without the CZ groove and escucheon+screw+bolt setup, not wanting changing humidity to affect too much pressure-change from the forearm. It shoots under MOA any one day, but I haven't tested across different humidities.

I bed the under-barrel lug into epoxy that is anchored around a 1/4" all thread cross bolt cut into recesses in the forearm channel.

I had them do that on the barrel of my last 416 Remington that I had built on a CZ 550 action . Had my gunsmith turn the sides so it looked the same as a factory CZ barrel.
It worked fine. That rifle was a 1 moa shooter that I believe I could have tightened up the group on with some accuracy reloading. It was a good killer.

All my rifles from 9.3×64 on up have or get under barrel recoil lugs. If I get another 375 Ruger, it will get one. My 375 Whelan AI does not have one yet and I don't know if it will. But , if I get any stock problems from it . That is the first thing that will happen. For me , having a stock break is potentially catastrophic. There are enough things that can go wrong with a rifle that are unknowns . I've had many stocks bust up in the action area . too many to continue to allow it to keep happening.

quote:

Originally posted by RIP:
TII = 25/44 = 0.57, almost as good as the 0.50 of H4350 in the .375 Weatherby,
and better than most.
I sure won't badmouth a ball powder in the .458 WinMag, if that ball powder is AA-2230.

Rip
.

Hi RIP (and others);

I'm Bob Mitchell, btw. Try H335 and you'll get about the same results, or close enough.It'll take a couple more grains than 2230, but it's (as you know) a ball powder. Check what the Hornady manual has to say in it's intro to the .458 WM about H335, as well as for the Lott.

On my own, I discovered that powder (H335) to work wonders in my CZ550. Easily got 2200+ from the 500 Hor. at MOA or better. And I didn't get that info from Hornady or Hodgdon. But Hodgdon (#27) shows 75.5 grains of H335 (NOT compressed) behind the 500gr Hornady RN @ 2163 fps and 50,300 cup (55,330 psi). That from a 24".

AA2230 wasn't available in this area when I did all my tests and hunting with that CZ. I waited two years before I got a one lb can. It worked very well, but not that much greater than H335 (which is readily available here) in my experience. I use WLRM primers.

That rifle was sold in 2011, but I sure took a lot of flack from members of AR (including the moderator) over the loads I published in 2010.

I'm happy to see this revival of sane ballistics for the great .458 WM. It still is one of my all-time favorite cartridges. If it were not for my age (81), I'd cherish another.

But I do have my favorite of the last two decades, a Ruger No.1 in .45-70 with an improved throat (.30"). I can seat heavy bullets to match standard .458 WM COL. And it gives equal ballistics.

I've published a manual on each and here is an example of ballistics from my Ruger No.1 in .45-70 LT (Long Throat) with original 22" barrel:

500gr = 2198 fps instrumental at 15 ft. (H335)
450 AF = 2305 fps " " (H335)
350 TSX = 2556 fps " " (from H4198)

I've also tried AA2230 in the Ruger.

Before I had the throat lengthened in the Ruger, I had a test done for me in a US lab on a load I used in my first Ruger #1 in .45-70. The bullet was the 500gr Hor. RN but crimped into the cannelure at 2.93 COL. It shot MOA at 2015 fps. The test was done with a 24" but at 2.83" COL. They got 2096 fps at safe psi (they used psi piezo) according to the chief ballistician, who phone me with results.

With the longer COL I use a slower powder.

Yesterday at the range:sighting the 500gr Speer GS and the 480gr DGX at 50 yds.

About 1700 fps for the Speer from 63grs RL-15, and 1750 (approx.) from the 480 with the same load.

The Speer shot 1" at 50, and the 480 into 0.45" (a ragged hole) from 3 shots each. Recoil about 45 (depending on whose formula -- I use three: Sam Fadala - which I put to memory many years ago = 40, Real Guns = 50, and the one you mention = 45)

Now sighted dead on at 100 for bear. Energy = 3263 ft-lbs from the 480, and mom. = 120 (Keith). Just want to try that flat point DGX on a bear to see how it works.

Shot one many years ago from the same current Ruger using the 500 Hornady RN at an MV of 2185. Hit behind left front shoulder and made exit in opposite flank. Bullet never expanded, but a two-foot loop of bowel was exposed that never ruptured. It was pinched by a 1/2" exit wound! The only way that could happen would be because that exit wound was much larger than 1/2" when pressure forced the bowel (intact) through that opening. I had a devil of a time getting it back inside without puncturing it!

Anyway, thanks for a GREAT thread!

Bob

www.bigbores.ca

an open mind ==

well it can be such a beautiful thing

people that don't know that they don't know are not the folks to follow

Bob knows the 458 win mag

quote:

That rifle was sold in 2011, but I sure took a lot of flack from members of AR (including the moderator) over the loads I published in 2010

Glad to have you posting Bob

love your blogg

we all on this thread can and will benefit having you post

now get to work and tell us all about the 458

I for one have been stealing loads from you for years

In reply to Bob's post of the Bear. I shot a whitetail doe with my 458 and a 433 grain Cast bullet last year, dead in the chest and the bullet exited at the flank. Most of her intestine was out that same smallish hole. I had no explanation other than the one you surmised. MV of about 1750 and shot at about 10 yards. Darned sure dead though! I just started the knife in the hole and then field dressed the doe.
I just took a look at your Blog Bob and thus will also bid you Shalom!

Bob,

Thanks for the reply to this thread.
Since stradling's mention of you I looked up your blog(s). Have about 8 bookmarks of them and have not read them all, yet.

I never made the connection to your old posts on the .458 WinMag, but will have some fun looking them up.
Surely I was in agreement with whatever you were saying back then, as I am now.

Thanks for the tip on H335.
It works great for me in the .223 Rem.
Will add it to the .458 WinMag repertoire.

Field dressing game with one bullet:

I did that to a fallow deer one time, a doe, at 342 yards by laser rangefinder, IIRC.
I was using a .416 Rigby with 350-grain Barnes X-Bullet.
The MV of that load was not as fast as your .458 WinMag 350-grain TSX, top load.
I hit her in the brisket on a broadside shot, and her belly unzipped in the midline. Intestines popped out on impact.
I have it on video tape, VHS from about 1999 or thereabouts.

How many orders for your .458 WinMag handloading manual do you need to get it printed again?

I'll bend the knee to you on the .458 WinMag.
I hope I have another couple of decades to catch up to your experience level with it.

Squirrel season is coming ... GOR
Rip
.

I was once confused about the throating differences between the .458 Win.Mag. and .458 Lott.
At one time I thought they were throated the same, or actually did not know how they were throated. I was ignorant.
Who knows how James Watts and Harvey Anderson throated the .450 Watts in 1949? Not me.
Might be an interesting bit of trivia.

Eventually the Lott got standardized by SAAMI.
The .458 Lott just makes up in brass length what it lacks in throat length.

Here is a post from Bob in 2008:

quote:

Originally posted by .458 Only:
RIP:

According to Hornady's Handbook of Cartridge Reloading, Seventh Edition, 7 powders will get you 2150 fps shooting their 500 softs or solids.

They show 76.3grs H335 to attain that speed. I use 78grs in my CZ for an even 2200 fps consistently with less than 10 fps ES. They recommend H335 for it's accuracy, consistency and "excellent resistance to extreme hot and cold conditions".

As to Aagaard's comment on the 458WM freebore, here is his quote from G&A's Big Book of CARTRIDGES, 1998, pg 77: Quote: "Frankly, I think that designing the .458 chamber with that long free-bore was a mistake, much more so than giving it a short case". end of quote.

From lemons comes lemonade.

Phase two of ".458 Win.Mag. Cast Bullet Handloading for Dummies" is ready to go.
Working my way down in velocity.

I will let the barrel cool by alternating with chronographing the .410 Eclipse,
hoping to see the .410/210-grain XTP vaporize on the way to the target.
The throat of that one is classified, cosmic-squirrel secret.

Squirrel season is coming ... GOR
Rip
.

RIP when I get to the shop today I will get the big boys to pull some measurements off the 458 win mag and the lott reamers

SEE IF WE CAN FIGURE OUT WHAT THE LOTT GUYS ARE DOING WITH THE FINGER NAIL FILE PROCEDURE

post it here


for the convenience to the readers of this thread on the 458 win mag

a link to Bob Mitchell s blogg

https://bigborefan.wordpress.c...8-win-mag-advantage/

Here's a comparison of the two SAAMI cartridges of most common interest nowadays:

Bigger:

Biggest:



Squirrel Season is coming ... GOR
Rip
.

One can figure out what happens when a .458 WinMag is rechambered to .458 Lott by looking at the above:

You get a .458 Lott with throat that is entirely comprised of the last 0.832" of the .458 WinMag's leade-only throat.

That might give the hybrid-throated .458 Lott some extra mojo, allow higher velocity, lower pressure, or both,
than the standard SAAMI .458 Lott.
But it will not be the best for standard .458 WinMag ammo fired in that chamber,
since the .458 WinMag start of throat has been widened to .458 Lott brass diameter for about 0.3".

One may eliminate the entire .458 Lott chamber (including throat)
by cutting off 0.5" at the breech,
set back the barrel,
and re-chamber to .458 WinMag.
It will be pristine!
Pure SAAMI .458 WinMag!
New rifles from old!

And that old .458 Lott converted to a new .458 WinMag is likely to have a box length of +3.6"
or even +3.8" if on a true magnum action.

So the "new" .458 WinMag can be loaded as long as even the .458 3-Inch Express,
if the bullet is long enough,
and some 500-to-600-grainers surely are.


Squirrel season is coming ... GOR
Rip
.

what about re-boring to a 458 AccRel?
It looks like a little free bore could work wonders and move things toward 450 or 450-short(2.5").

Twist my arm, but I really don't like the idea of hunting below 2400fps.

ALF

barns bullets cut groves in the long monolithic bullets

less surface contact w the rifles

seems it helped a lot

they seem to still use it

driving bands and so on

you're not wrong

but are there workarounds for the long bullet pressure jump issue

one of the projects we are just now loading for

a 35o grain woodleigh bullet in a 375 hh for a rather ambitious customer

no groves in that one we will see pressure at higher velocities I expect

not saying 2200 fps would be to slow on a bullet of that wt

hard to beat the flexibility of a 458 win mag

that first bullet in RIP'S bullet pic just might run out the barrel ok with the pre cut barnes bullet groves reducing pressure as it engraved and spins down the tube

if so a bit more case volume for the push power

quote:

Originally posted by mlazarus:
.......................................
On a side note, how is it that so many consider the 375 a suitable DG caliber but will argue the merits of the decidedly more powerful 458 WM in the same role?

Because some people on the internet will argue about anything.

check out the velocity Bob got with this 350 grain barnes

in the updated 458 win mag blog he hosts

https://bigborefan.wordpress.c...ster-magnum-updated/

and then WHY THE 458 WIN MAG MIGHT BE ENOUGH

https://bigborefan.wordpress.c...um-is-enough-part-2/

quote:

Twist my arm, but I really don't like the idea of hunting below 2400fps.

I shouldn't, but , what's wrong with a 500 gr bullet @ 2150 fps.
Moving a 500 gr bullet at 2400 fps is ALOT more recoil . I never noticed that a 500 gr 458 bullet at 2000 + fps lacked killing ability. Put the bullet close to the correct spot and it was on the ground.
I like and prefer lighter bullets going faster. But I have an idea that I will end up with a gran paw load of a 400 gr bullet @ 2150 fps.
Hopefully I can get a cast boolit load to do that , and get a jacketed , tough bullet to print in the same place. I doubt that much of what I hunt will walk off from a good hit from that.

. it's kinda like driving.
A brand new , jacked up , hotted up 3/4 ton 4 wd pick up may be cool and cost lots of money. But an old 7000 series GMC flat bed work truck will go the same places and get more work done.

ONE MORE ADVERT FOR BOB

HE IS TELLING IT LIKE IT IT'S IN THIS ONE

A MUST READ

https://bigborefan.wordpress.c...ster-magnum-updated/

I think I know a few of the jokers he refers to in the introductory paragraph where he tells of a major hunting and shooting forum back about 8 years past


CTF you can even take a cute little gal on a date in an -- 7000 series GMC flatbed work truck

MAY turn out to be the best fun you ever had-- not near as much fun-- but shooting squirrels with a 458 for some reason -- deeply satisfying

On the subject of cast bullets the large throat of the 458 Win mag can't be helping. Some people report good results using the stock throat but they are not common. Most people report mediocre cast bullet results at best. Given the cavernous throat that offers no support to the bullet, that is hardly surprising. The 375BB has a throat that is similar and I suspect it was also designed to blow off pressure quickly, just like the 458WM.

For best accuracy cast bullets need to be supported in the throat. Even so called 'hard cast' bullets cannot endure the transition through such a long and wide throat. You can get around this though. In the 375 BB I cast bullets so large in diameter that the loaded shell just fits the chamber and therefore sits concentrically in the chamber. Without such support the bullet slumps to the bottom of a cavernous throat causing poor accuracy. With the 375BB you cannot load a cast bullet that would be supported by the long throat and still have it work through the action.

Lyman at one time produced a mould that was apparently designed for the 460 WBY but it would work well in a 458WM. It was designated 462560 - the base diameter was typically 0.462/0.463 and weight was around 560 gr and it was a GC design.

The objective is to have a bullet that is supported at the rear, fills the chamber and still functions through that action. This will centralize the cartridge relative to the long, wide throat. Once the cartridge is fired the bullet remains supported in the rear until the front of the bullet contacts the rifling at the end of the throat.

Another alternative would be to use paper patch bullets to achieve the correct diameter. Those that have used paper patched bullets in a 458WM report excellent accuracy. If you use a hollow base bullet design for the paper patch bullet, the rear could expand to conform to the large diameter throat and provide even more support through the transition.

Hope this helps.

quote:

Originally posted by Fjold:

quote:

Originally posted by mlazarus:
.......................................
On a side note, how is it that so many consider the 375 a suitable DG caliber but will argue the merits of the decidedly more powerful 458 WM in the same role?

Because some people on the internet will argue about anything.

I kinda think it comes down to recoil. I would be willing to bet that most people shoot a 375 H+H more accurately and faster than they do a 458 . bullet weight equals recoil . A 400 gr bullet @ 2400 fps recoil less than a 500 gr bullet @ 2150. Tho they are close. A 300 gr bullet at 2530 fps isn't even in the same category as the 2 fore mentioned loads . All of them being shot from a 9 lb rifle.
When I had my wife being my bear watch at 8 Fathom Bight. I made up a load with the 300 gr Barnes TSX going 2530 ish fps. She was able to shoot it and not be all discombobulated by it . If I had her try to shoot a 500 gr load at 2150 fps. When she recovered , she probably would have shot me with her 357 mag Ruger Blackhawk.

quote:

Originally posted by stradling:
check out the velocity Bob got with this 350 grain barnes

in the updated 458 win mag blog he hosts

https://bigborefan.wordpress.c...ster-magnum-updated/

and then WHY THE 458 WIN MAG MIGHT BE ENOUGH

https://bigborefan.wordpress.c...um-is-enough-part-2/

In the words of a Jedi Master, may the .458 Winchester Magnum Force be with you.

In yon link above, Yoda Bob said this, for the record,
go to the links for a better experience (more pictures) than this copy from one of them:
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Posted by bigborefan on September 2, 2017

The .458 Winchester Magnum — Updated

It has taken eight years, but finally there is a post on a major forum that recognizes the full ballistic potential of the now historic .458 Winchester Magnum.


(The CZ550 in .458 Winchester Magnum .It was loaded for bear using the 350gr TSX.)

On that forum, I became a member nine years ago and began posting my results from handloads of a CZ550 in .458 Winchester Magnum. Not only did the moderator himself but many other powerful and influencing members gave me a tongue lashing you wouldn’t believe! They indicted me for not only publishing loads that were “impossible” but down-right dangerous that might get someone killed from an exploding rifle! At least that’s my lasting impression of the verbal exchanges of that era. Yet today, on the same forum, there is an extended presentation of several pages on the excellence of the great .458 Winchester Magnum. There are still a few naysayers, but on the whole the discussions are very positive with a great deal of sane testing results presented that bode well for the future of a very versatile cartridge that has proven itself to be one of the best for anything from hogs to elephant. There are several proofs for the justification of that belief and statement.

What are they?

FIRSTLY: My own experience. Of course, that is not objective proof for someone who doubts the probability of my results. But then, it has been, and still is, revealed time and again that some on the forum in question will not accept the outcome of tests presented by honest people — regardless of the objective data submitted. So, frankly, I just ignore such prejudice from those who pontificate that the returns introduced in favor of the .458 Winchester Magnum are neither possible nor safe. Why? Because they choose to lie about the methodology employed in assuming that those who put forth favorable evidence are lying. You know that universal truth: Every thief believes that everyone else steals so that’s the justification for their thievery! Everyone lies, so that’s the justification for lying! They are unable to discern truth when it is staring them in the face! You know, I’ve been a professional in my “job” for exactly sixty years this month of September. During that period, I’ve counselled thousands of people whether from pulpits or one on one, and what I discovered long ago is that some do not want to hear truth if it contradicts their lifestyle or the way they think!


In my personal experience with a CZ550 in .458 Winchester Magnum, using common components found at gun shops, 2200 fps was EASILY attained, or surpassed, firing the 500gr Hornady RN Interloc at SAAMI specs. When seated “long”, which that action and magazine permitted, I EASILY attained 2283 fps from a common, “off the shelf” powder (All of this is in my reloading manual on the .458 Winchester Magnum.). And none of that was obtained from AA2230, which is perhaps the best all-around powder today for that cartridge. That gunpowder was not available in our area until well after I’d finished my own testing and hunting with that rifle. Just before it was sold, I received a call from a gun shop that they had a one-pound can of AA2230 reserved for me. I picked it up and gave it a try. 74 grains gave a corrected to muzzle MV of 2227 fps from the 500gr Hornady. That was at a COL of 3.39″. Had I seated the bullet “out”, I don’t objectively know what the results could have been. But from H4895, with that bullet seated long, I attained 2283 fps without any hints of undue pressure.

Moreover, my hunting load for North American big game was the 350gr TSX at 2700 fps. That was from using RL-7. After the moose hunt in N. Ontario using that rifle and load, I found that in colder temps it lost 100 fps, and the bullet hit several inches below where it was sighted for the moose hunt! I then switched to H4198 (one grain less) and got these results: (H4198, as well as H335 proved to be very temperature resistant gunpowders.)

2746; 2745; 2748; 2748; 2744;; 2746 and 2746. Average = 2746 instrumental. Corrected to muzzle = 2760 fps/5919 ft-lbs.

Had that been the load taken to N. Ontario for the moose hunt, and a bull had shown up within 500 yards, I’d have taken the shot! Why? Take a look at this:

Rifle: CZ550 in .458 Winchester Magnum (Weight with five cartridges = 11.25 lbs)
Bullet = 350gr TSX (B.C. from my tests = at least .338)
Barrel = 25 inches
Powder = H4198 (80 grains – taken from Barnes #3 for the Lott at 82 grains max behind the 350gr XFB with a single groove. The B.C. of that bullet is listed at .402! But the 350 TSX is the same bullet with a couple more grooves. The bullet was crimped into the bottom groove for my rifle.)
Primer: WLRM
Case: Winchester

Ballistics:

MV = 2760 fps/5919 ft-lbs (zero @ 250 yds)
100 = 2505 fps/4876 ft-lbs/+ 3.37″ trajectory
200 = 2264 fps/3984 ft-lbs/+ 2.77″
300 = 2037 fps/3224 ft-lbs/-4.65 ”
400 = 1824 fps/2585 ft-lbs/-20.48″
500 = 1627 fps/2057 ft-lbs/-46.81″

NOTES:
1) Trajectory is nearly identical to my 9.3 x 62 load of a 286 NP at 2622 fps.
2) Recoil = 51.5 ft-lbs (I never noticed the recoil of that load when used in shooting a bear)
3) This is material from my manual on the CZ550 in .458 Winchester Magnum.
4) Barnes declares that the 350 TSX will give some expansion down to 1600 fps impact on big game.
5) For a moose-size animal, just hold two feet over the hump at 500 yards. There is still plenty of velocity and energy at that range. As a friend says, “It’s like the .30-06 on steroids!”
6) During a five day hunt for a bull moose in N.Ontario, I never noticed the rifle’s weight or length, both of which contributed to steadiness of hold. The only condition where I would have wished for something handier and lighter was in moving through tight brush and alders. There, I would have preferred my former Ruger M77 in .458 Win Mag with it’s 22″ barrel and shorter action with overall weight at about 9.5 lbs. That too had previously gone on a moose hunt in extreme weather conditions.


(Average results from the 350gr TSX from my CZ550)

ABOUT B.C. (ballistic coefficient)
This topic is important for a number of reasons:

It is useful in helping to predict the trajectory of a given bullet. There are a number of easily accessible online programs, such as hornady.com and realguns.com. I’ve had one on my tabletop for years. There are places for input of muzzle velocity (which we must know) and ambient conditions, such as temperature, elevation and relative humidity. Also for wind direction and strength.

If we know the muzzle velocity of a given bullet and its B.C., we can then know its impact velocity and energy.

Then, taking into account the construction and shape of the bullet, as well as impact velocity, we then can generally have confidence as to results, or if that particular bullet is appropriate for our intentions. For example:Just now I’ve begun a testing sequence for a couple of .458-cal bullets. So far, I’ve only partially accomplished my first goal — their suitability at reduced velocity for shorter-range hunting of black bear, deer or a calf moose. The velocity will be about 1700 – 1750 fps.

Accuracy has significance that may be somewhat challenging, which has only partially been achieved in my current tests. But we want enough for the purpose envisioned So far it’s looking pretty good, especially from the lighter of the two bullets. The first was purchased only a few weeks ago, being a 25 count box of 500gr SPEER African Grand Slams. The other is a 480gr Hornady DGX that I purchased a few years ago, and have shot twenty of the fifty in two rifles, the CZ550 and my Ruger in .45-70. Just now they are being tested in my Ruger. At 50 yards, three Speers went into 1″ and three DGX went into a ragged hole at 0.45″. The Speer was chronographed at 1700 fps and I assume at the moment that the 480 is doing about 1750 from the same charge of powder. I’ll test that bullet over the Chrony to be certain of that assumption. It has a flat point verses a RN of the Speer with a lot of lead exposed. More tests coming to confirm accuracy at 100.



While this has little to do with B.C., yet it’s very important. It has to do with penetration tests. That will be upcoming and reported on. I use dry glossy magazines in a cardboard box… this is a tough test for any bullet and simulates bone. I’m expecting the DGX to out-penetrate the Speer 500gr AGS, but the Speer may make a broader cavity. We’ll see.

SECONDLY: (as proof) At least four of the reloading manuals in my possession give loads that reveal muzzle velocities for 500 grain softs and solids in EXCESS of 2150 fps. These results are from Hornady, Hodgdon, Barnes and Accurate Powder. The average for 500s is 2188 fps/5317 ft-lbs from 24″ test equipment. Interestingly enough, former writer and PH, Finn AAgaard, tested .458 Win Mag factory ammo in five rifles, and his own 23″ semi-custom .458 gave the best results from a 500gr Federal Premium load at 2188 fps without a hint of excessive pressure!

THIRDLY: (as proof) the current thread on Accurate Reloading Forum (referenced at the start of this article) under “BIG BORES, .458 Winchester Magnum”, provides ample proof against any possible legitimate argument that the now historic (and in my view “great”) .458 Winchester Magnum is more than capable for any large and dangerous game on this planet!


(My load for moose and bear in the CZ550. A bl. bear was cleanly taken with this load)

Of course, all that has been demonstrated since “forever”. A close friend and buddy who went to Kenya in the early sixties as a teacher/administrator at the famous Rift Valley Academy, took two Winchester rifles for personal hunting of big game: a Model 70 in .300 Win Mag and a Model 70 in the original .458 Winchester Magnum African. He shot “truckloads” of DG and plains game, including many Cape buffalo and elephant with the supposedly “weak” factory ammo of the era! Amazingly enough, he never once recognized any weaknesses on those beasts, or complained about it! He used the sale of the elephant tusks to finance his and his family’s furloughs to Canada.

ABOUT S.D. (sectional density)

S.D. is explained in several ways, but the simplest and most common is to state that it’s the ratio of weight to the diameter of the bullet. Of course, bullets may vary in diameter, especially the nose profile. But assuming the bullet was a cylinder of a particular weight, the formula would look like this: the weight of the bullet in pounds divided by the square of it’s diameter: (example: a 500gr in .458-caliber) S.D. = 500/7000 = 0.0714285/0.209764 ((.458 x .458 = .209764)) = .3405 S.D.)

The Hornady Handbook, 9th Edition states: “Bullets of the same shape but with more weight in relation to their diameter retain their velocity and energy better”, pg 912.

I would add: “and same construction also penetrate better, other factors being equal”. That’s why, for example, that for large-tough game where penetration is a must to break bone and reach vitals, the heavier (or “heaviest”) bullets are used in a given caliber even though energy may be equal at impact. It’s a demonstrable fact (I believe) that a 330gr FP solid in .458-cal at 2612 fps MV (5000 ft-lbs) will be out-penetrated by a 500gr solid FP at 2122 MV (5000 ft-lbs), if construction and shape are the same, in a frontal impact on a bull elephant. Why? Because for the 330gr to have the same momentum it would have to leave the muzzle at 3215 fps! Plus, it will lose it’s initial velocity much quicker as S.D. is a real factor in B.C. as well. I have some 330gr Barnes Banded Solids in .458″. They have a FP and their B.C. was rated at less than .200 (before they were “Banned”!) whereas their 500gr Banded Solid FP is rated at .394! The 330s shoot well and give excellent velocity from my Ruger but I’m unsure they’re legal for anything this side of the pond. But which would you choose for elephant? In ALL the videos I’ve watched on elephant hunting, heavyweight bullets per caliber were used with high S.Ds.


(A 480 Hornady DGX and a 500 Hornady Interloc RN – with the tip made flat on purpose to give better effect)

I’m firmly persuaded that for large-dangerous game where breaking of bones is often a necessary factor, as well as deep penetration, nothing beats a large caliber employing bullets of proper construction with high sectional densities. Of course, bullets must be placed where they will do the most good (harm).

The .458 Winchester Magnum leaves nothing on the table in that regard. With today’s bullets and powders, it is better than ever.

Shalom

BOB MITCHELL

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Squirrel season is coming ... GOR
Rip
.

For those disparing that they own a .458 Lott,
be consoled by the fact that you can still get by with that over-long brass.
It is as simple as running a SAAMI .458 WinMag reamer into your .458 Lott rifle.
Voila!
You now have a .458 Longclaw.
That is a .458 Lott with .458 Winchester Magnum MOJO.
Here is a drawing showing the throat of the .458 Longclaw.
The cartridge drawing is the same as for the .458 Lott.
The .458 "Lott More" Longclaw is hereby released to the gun trade by RIP-off Arms Company, LLC.

And those who have had their SAAMI .458 WinMags converted to .458 Lott using a SAAMI reamer for the .458 Lott,
cheer up.
You already have a .458 Longclaw.
Me too, got a couple.
It ain't so bad except for being stuck with 2.800" brass.
Performance of the 2.5" brass is degraded, but it will still do pretty well in a pinch.



Squirrel season is coming ... GOR
Rip
.

Alf,

Are you "putting words in my mouth?"



I said the current bullets were long enough,
and showed photographic proof of 3.700" 600-grain load that will chamber in the .458 WinMag.
That is Ye Olde Barnes Original RNSP .458/600-grainer.

I also showed a 3.797"-long 500-grain load with the original iteration of the Barnes X-Bullet .458/500-grainer.
I have since been able to put a cannelure on that one also, and crimp it at exactly 3.800" COL.
That chambers in the SAAMI .458 WinMag also.
The newer .458/500-grain TSX FB has a blunter ogive and cannot be seated that long,
see the "NO GO" dummy that is only 3.788" long.
Just a reminder that I see you badly need:



Other than your little misunderstanding on the supposed need for longer bullets,
I agree completely with your words below.
Those danged ol' South African powders were a mess, eh?

The .450 Majoor (Short & Long) reminds me of my .458/.338 "Lopwah" Magnum. I now call that one the .450 Ted Williams Thumper,
because .450 is what Ted's batting average would have been in 1941 under current rules.

quote:

Originally posted by ALF:
RIP
Slow down buddy you are going to stroke out on the "458 cool aid" you are drinking.

"IF THE BULLET WERE LONGER"

Are you not forgetting something ? PRESSURE !

In all of this clamour no one has actually sat down and actually proofed as single one of these proposed recommendations and assumptions ?

A longer bullet means increased pressure.

Now Koos Barnard who developed his version of the 3 inch express (aka Ken Stewart aka Venter) played with all manner of bullet and pushing length ie increasing SD increased pressure substantially ! and as per South African Law at the time each and every modification required proofing by the SABS and this confirmed what they were seeing in practice. Sticky case and blown primers when the SD of the bullet was increased. It soon became apparent that the 458 3 inch had a bullet weight limit that required down loading which then brought it back to a standard 458 Win. Basically a efficiency limit as determined by the yield strength of the case.

Incidentally Jurie Majoor ( I dont know if he s still alive ) developed a duo of beltless 460's namely a 450 Short Majoor and 450 Long Majoor
a short and full length 416 Rigby based 458. The long was essentially a beltless 460 Weatherby.

The 450 Short Majoor a 458 length 460 Weatherby without the belt.

Mauritz Coetzee ( since passed on to happier hunting grounds) ran into the same pressure problems with his Short Majoor.

What was very interesting was that on one occasion Mauritz Developed loads on the highveld in Pretoria and when he took them down to the lowveld the cases stuck and primers backed out. They had gone down to the Lowveld to do a reloading course with Lowveld hunters association in Phalaborwa when this actually happened on the range.

As A side note Mauritz did the same with the 45-70. He had a Ruger No 1 in 45-70 and he pushed the red line on the 45-70 long before any of the modern super loaded 45-70 saw print in American gun rags.

Squirrel season is coming ... GOR
Rip
.

quote:

Originally posted by JFE:
On the subject of cast bullets the large throat of the 458 Win mag can't be helping. Some people report good results using the stock throat but they are not common. Most people report mediocre cast bullet results at best. Given the cavernous throat that offers no support to the bullet, that is hardly surprising. The 375BB has a throat that is similar and I suspect it was also designed to blow off pressure quickly, just like the 458WM.

For best accuracy cast bullets need to be supported in the throat. Even so called 'hard cast' bullets cannot endure the transition through such a long and wide throat. You can get around this though. In the 375 BB I cast bullets so large in diameter that the loaded shell just fits the chamber and therefore sits concentrically in the chamber. Without such support the bullet slumps to the bottom of a cavernous throat causing poor accuracy. With the 375BB you cannot load a cast bullet that would be supported by the long throat and still have it work through the action.

Lyman at one time produced a mould that was apparently designed for the 460 WBY but it would work well in a 458WM. It was designated 462560 - the base diameter was typically 0.462/0.463 and weight was around 560 gr and it was a GC design.

The objective is to have a bullet that is supported at the rear, fills the chamber and still functions through that action. This will centralize the cartridge relative to the long, wide throat. Once the cartridge is fired the bullet remains supported in the rear until the front of the bullet contacts the rifling at the end of the throat.

Another alternative would be to use paper patch bullets to achieve the correct diameter. Those that have used paper patched bullets in a 458WM report excellent accuracy. If you use a hollow base bullet design for the paper patch bullet, the rear could expand to conform to the large diameter throat and provide even more support through the transition.

Hope this helps.

Good post.
I thought about getting a mould made to fit the .458 WinMag throat for cast bullets,
then realized that I would then have a rebated-base bullet,
a portion of which would have to squeeze down from at least .469" diameter into a .450" bore and .458" groove diameter.
Applying a .45-cal gas check by wobbling that bullet nose through a .47-cal sizing die ...
That is a bit wild to say the least!

My second installment of "Cast Bullet Handloading for Dummies" may happen later today, or tomorrow,
Lord willin' and the creeks don't rise.



Squirrel Season is coming ... GOR
Rip
.

quote:

Originally posted by Cold Trigger Finger:

... what's wrong with a 500 gr bullet @ 2150 fps ...

Not a thing! Yep, you got that right.

I like and prefer lighter bullets going faster. But I have an idea that I will end up with a gran paw load of a 400 gr bullet @ 2150 fps.
Hopefully I can get a cast boolit load to do that ,

Dream on! I think 1900 fps is too fast with cast!
Hoping a pleasant 1200 to 1600 fps is in the accuracy zone. Fingers crossed.

and get a jacketed , tough bullet to print in the same place. I doubt that much of what I hunt will walk off from a good hit from that.

Today is the day!

Squirrel season is coming ... GOR
Rip
.

You guys are making me think that the 308 should out-pace the 30-06 and maybe even the WinMag. But even though I think the 308 is cute and a good caliber, I would be interested in its possibilities in a 2.5" case and maybe about .2" free-bore.

But back to the .458" diameter, all you'all have made a good case for a 2.5" 458 heavy hitter. this leads me to a natural follow-up question. Has anyone made a die and reamer for a "Ruger" case run into a .458" neck? It would do "Lott" but not as easily as the 458 AccRel. To really see the advantages, Ruger might want to put out a 3.6" action, or else we can use the Win70, or go whole hog with the CZ. I think that a 458 "Ruger" would be a cute round. (Frankly, I'm partial to .489" case-heads as bores move to 45 and 50. RIP, I think you used to understand that.)

Sometimes its very hard to separate discussion from heated Arguments on the internet, must be the lack of sounds made by the human voice..Discussions over a campfire seldom meet with such vocal proclaim..Too bad! but were all guilty at times..We do love our old betsys!