Fury01,
Buy a donkey for noticing those BHNs.
That little Lee kit is fine as frog hair.
I tried the LBT tester, and think it is useless in comparison to the Lee:



I think the example reading shown above is 0.050" = 20.9 BHN from the chart below.

This makes sense for demonstration on a common standard of BHN: Linotype
And that is exactly what I got from my Linotype in using this kit.

.458 WINCHESTER MAGNUM PERFECTION

Non Illegitimi Carborundum

quote:

Originally posted by The Maz:
RIP - I'll use some older Remington factory loads with the 450 grain A-Frame as a "reference load" with the newly installed gauges. Once I have a baseline, the real fun can begin!

That will be very interesting.
Whatever you do, it is all good, for extrapolation.

In my experience, the Swift A-Frames give lower MV than most other bullets for the pressure applied to them.
Those are supposed to have a 60,000 PSI MAP, so should be no more than that.
They are probably significantly less in pressure,
since the .458 Winchester Magnum got no respect during the dark ages of the Lottite Insurrection,
when the anarchist Lottites rioted and looted.
Lottites do so remind me of the U.S. Dimwitcratic Party,
who have been holding their National Convention in the streets of so many cities all over the USA,
for some weeks now.
The official start of the convention was outside the White House in Washington, D.C., late May 2020.
Some got started earlier, none of them know when to quit.

The First Edition of Bob Forker's AMMO & BALLISTICS shows MV of only 2150 fps
for the Remington 450-grain Swift A-Frame Pointed SP (RS458WA).
G1 BC = 0.310

.458 WINCHESTER MAGNUM PERFECTION

Non Illegitimi Carborundum

Of course, I'll also test with my go-to load of 70 grains of IMR 4895 and a 500 grain Hornady Interlock loaded to standard length.

Interesting thing with the Ruger No. 1 is that I have never been able to even slightly flatten a primer in that rifle with 4895. Maybe I can try to do so with H335, though I doubt that will happen.

I also have a LabRadar chronograph, so I can measure the MV of the test loads as well.

about 35 years ago I decided to have a Rem 300 Win Mag re-barreled to a 375 HH and the gunsmith talked me into a 458 Lott so my big bore was born. well pushing Barnes 400 gr Spitzer Bt (discounted) and running about 1 1/4" groups out at 2500 fps with a lot of Reloader 7 can't remember how much all the case was full and always shooting off the bench at the local gun range (you could not stand to fire there) it became to much,started taking 4 aspirins on the way to the range so I had the barrel pulled and sold it to a guy that put it on a Mauser action and went to Africa and told me he shot a lot of animals with it. at least my barrel went there as I have never gotten there. so no last year I decided it was time to go back to the Lott and started looking but just kept looking until one day I discovered this web site and started reading all the pages on the 458 mission and was hooked on a 458 Win V so I found one at Cabelas in Boston, Mass at a very good price and it was brand new according to the Gun Library manager there so I purchased it and low and behold it was new as they said all the factory paperwork was there except the factory manual which I got from CZ USA and the gun is the Safari model 550.so after a bunch of info from them members on this site I had it glass bedded and I cleaned it up real good, the factory test target shows a 3 shot group of about 1 1/2 inches. the surprise was the gun was built in 2008. so now to the loading bench and with some advise of RIP started working on loads with the 350 gr Hornady bullet settled on a load of 78.0 gr of AA2230 powder and a length of 3.122 average of 2551 fps and 3/4" group at 50 yards. now using the Barnes 450 gr TSX at 3.673" and loading 78.0 gr of AA2230 powder the loads averaged 2310 fps with only only 10 fps spread, the groups run at 1/2" at 50 yards and if I looked it up correctly 5333 pounds of energy and at 77.0 gr same powder average was 2290fps and 5100 pounds of energy and only 3 fps spread I think this is the load I will use. all n all I am happy that I did not buy a Lott as this will work out great so the next loading will be 400 Barnes TSX as soon as they can be talked into making them as I do not have the equipment to make them from 450 gr bullets as RIP talked about doing.thanks for reading sorry it was so long. Jim

Thanks for your story hydehunter.

If you've read The MISSION journal here, you know most of my story. My 2nd .458 was the CZ550. It had the long Mauser action and SAAMI "freebore", so no need to make it into a Lott. From the beginning I just used the benefit of that long leade, making it the equil of, or better than a .458 Lott. That was (now) over a decade ago.

My 3rd .458 is the #1 Ruger, seen on the header of my web page.

In my view, the .458 WIN is the best of the Big Bores when all is taken into consideration. It is one of the most -- if not THE most versatile cartridge extant. Again, from my perspective, more so than the great .375 H&H of which I've owned several.

I know your appreciation will grow with experience.

Bob
www.bigbores.ca

I wonder how a non deforming solid hydro-Wadcutter would perform terminally. For DG in the 458 it should be an interesting option. Instead of having a funky shoulder on the nose, just a radius edge and a concave nose. The BC would be bad but it would be heavier for bullet length. Perhaps a good pistol bullet. I will TM them as Bullnose Solids or BS Bullets

just told my wife that I think I might just go to one of the Indian reservations this winter and get myself a big bison and see how well the 450gr TSX will do

quote:

Originally posted by The Maz:
Of course, I'll also test with my go-to load of 70 grains of IMR 4895 and a 500 grain Hornady Interlock loaded to standard length.

Outstanding combo but I would choose H4895,
which is faster at lower pressure with the light bullet loads in the Hodgdon Annual Manual.
Hodgdon owns both powders, but they do not even show IMR-4895 with 500-gr bullet.
They do show H4895, with 500-gr Hornady Jacketed Round Nose
COL 3.310", WW brass 2.490", CCI-250, 24" barrel 1:14" twist:
H4895 70.0 grains >>> 2108 fps/ 36,100 CUP ~ 42,598 PSI
H4895 74.0 grains (Compressed) >>> 2161 fps/ 50,300 CUP ~ 59,354 PSI

Interesting thing with the Ruger No. 1 is that I have never been able to even slightly flatten a primer in that rifle with 4895. Maybe I can try to do so with H335, though I doubt that will happen.

Interesting you say that.
In the mid 1980's I was able to get excessive pressure in a Remington M700 Safari .458 Win.Mag.
Probably minimum groove diameter 0f .458" and minimum SAAMI throat, and I doubt the bullets were undersize.
I did not measure such things back then.
I did it with IMR-4198 and the 400-gr Swift A-Frame bullet at just over 2400 fps instrumental.
Brass extrusion ejector marks showed on the headstamp area of the R-P case, finally one primer was pierced, flattened, smoked its circumference,
and fell out of the case.
Well after that I got similar results with a Remington factory-loaded .375 H&H with 300-grain Swift A-Frame.
I pulled the bullets and later heard of a recall on that ammo.
I use A-Frames only slow and low pressure now.
In my resurrection of .458 WIN+P shooting with all other bullets,
I have had 4 loads developing +6000 ft-lbs KE with TSX and Woodleigh bullets, and .459"-grooved, SAAMI-throated barrels, 24-7/8" to 25" lengths:
350-, 450-, 500-gr TSX
400-gr Woodleigh PP SN

Yes, primers are flat and flush with no cratering of the firing pin indent, but no brass extrusion marks at all.
No sticky extraction. No funny business. I do not measure case head expansion.

I also have a LabRadar chronograph, so I can measure the MV of the test loads as well.

Unfortunately I have only bagged 2 of the 6 optical chronographs I have owned.
When I have culled the rest, I too will get a LabRadar.
.458 WINCHESTER MAGNUM PERFECTION

Non Illegitimi Carborundum

quote:

Originally posted by hydehunter:
just told my wife that I think I might just go to one of the Indian reservations this winter and get myself a big bison and see how well the 450gr TSX will do

hydehunter,

Yumpin' Yehossaphat !
You figure out how to do that and let me know.
I will do it too.

I spent over a year on the Pine Ridge Res, working as a Lakota Medicine Man for the IHS.
Also worked at a couple of other Rez facilities in my traveling days.
Did a lot of sight seeing during time off,
but never got around to bison there.
I truly love The Great State of South Dakota.
And you have a Brightwit Governor right now who shines amongst so many Dimwitcratic governors.

That 77.0 grain charge of AA-2230 has been an accurate performer with all 450-gr bullets I have tried, North Fork, CEB, TSX.
COL 3.360" with CEB Safari Solid at 2343 fps 5-yd chrono/ 2365 fps MV, 0.53-MOA 3-shot
COL 3.485" with North Fork FP Solid at 2348 fps 5-yd chrono/ 2360 fps MV, 0.69-MOA 3-shot
and now,
in your rifle, yes,
"I" tried it in your rifle:
COL 3.673" with Barnes TSX at 2290 fps 14-ft chrono/ 2301 fps MV, surely sub-MOA after you get comfortable with it.

When I started in with North Fork 450-grainers I went from 76 to 81 grains of AA-2230 and 76 to 81 grains of H4895.

With the 450-grain TSX I did not bother with low charges, went straight to 80.0 grains of AA-2230 as a starting load at 3.680" COL.

Thanks for checking the 77.0-gr and 78.0-gr charges of AA-2230 for me.

Allowing BC = only 0.369 for the 450-gr TSX, and call it a 5-yard distance to chronograph:

Your 78.0-gr load velocity, corrected to MV is 2321 fps, 5382 ft-lbs KE.
77.0-gr load velocity, corrected to MV is 2301 fps, 5290 ft-lbs KE.
I shall rely on your data in my CZ and Shilen barrels of 25" length, 1:14" twist.
.458 WINCHESTER MAGNUM PERFECTION

Non Illegitimi Carborundum

boom stick,
Catchy name and logo photo,
but, it will be tough to get your Bullnose Solid "BS" Bullet to feed in a magazine repeater,
and you will have to shoot it at barely over 3.100" COL in the mighty .458 WIN+P.

Sorry to say, Bubba Bullet Metamorphosis Tech will not be making any of those.
I suggest you refer that design to the Lottites,
they might be able to shoot it at 3.000" COL and it will jam in their magazines.

.458 WINCHESTER MAGNUM PERFECTION

Non Illegitimi Carborundum

It would be better for a single shot, lever action or pistol for sure. A 400 grain 458 Bullnose Solid designed for about .45” nose protrusion on a lever action could get to feed in a 458 WM would it not?

quote:

Originally posted by boom stick:
It would be better for a single shot, lever action or pistol for sure. A 400 grain 458 Bullnose Solid designed for about .45” nose protrusion on a lever action could get to feed in a 458 WM would it not?

Maybe. 2.95" COL in the .458 WIN+P.
Could not fit it into a .458 Lott chamber with that much nose projection.
Offer it to the Lottites.
Sort of like telling them to go sit in the corner of a round room.

.458 WINCHESTER MAGNUM PERFECTION

Non Illegitimi Carborundum

The draftsman at BBMT put his pencil to some graph paper, to display my data (warm orange) and compare it to that of hydehunter (cool blue).
A picture is worth a thousand words.
A picture with some words written on it is worth a thousand words and then some:



.458 WINCHESTER MAGNUM PERFECTION

Non Illegitimi Carborundum

you know after the barrel is finally broken in the velocity may go up on its own as the rifle has only had 18 rounds through it including the factory test fire I am very happy with it.if I can dig someone up with a lathe I will try shorting up the 450 TSX bullets to get them to 400 grains (since Barnes will not do it yet unless a lot of shooters ask them)and work on those loads then stop shooting off the bench,feels like my brain is being slammed into my skull (ouch) when I pull the trigger and trying not to induce a flinch, nice graph but it sure would be nice to get the 450 up to 6000 pounds of energy I guess I just like being beat up. thanks Jim

Hydehunter,
Buy a donkey for your excellent support of THE MISSION.
Yes, polish that barrel with bullets.
AA-2230 should be tried up to 100% fill.
The way I was getting diminishing returns after 82 grains might be due to compression of ball powder ?
I have since discovered that the stick powder H4895 seems to respond very well to compression,
getting 400-grainer to over 2600 fps.
With H4895 being just a little slower in burn rate than AA-2230,
but capable of pushing such a light bullet as 400-grainer faster than AA-2230,
H4895 might just get even better with the heavier bullets and compressed loads.
A shallowly seated bullet crimped securely over a compressed load of stick powder is a well secured load indeed.

And H4895 will be better for reduced loads with/without filler than the AA-2230, due to lower pressure with the H4895.

My next trick is to try the 401-grain 50:50 alloy bullet (water-dropped, painted and age-hardened to BHN 23)
with H4895 at presumably less than 30,000 psi,
maybe with 65 to 68 grains of H4895, trying for 1900 to 2000 fps velocity with good accuracy and low recoil.
Then see if accuracy goes south at higher velocity.
Even that slowball would beat an Elmer Keith .45-70 load he thought sufficient for elk.

Then a big jump in H4895 charge and work back up to the maximum load I started with,
using the 400-gr Woodleigh: Try 76 to 87 grains of H4895.

And after that I gotta do the 450-grain TSX with H4895 to maximum COL and maximum compression.
That is sure to make the Lottites cry.

.458 WINCHESTER MAGNUM PERFECTION

Non Illegitimi Carborundum

I too have found H4895 best for compressed loads of the 450 TSX and 500s (Hornady and Speer - not the 500 TSX as I don't have the latter anyway.)

The only apparent exception is using 84 grns H335 under the 450 AF. But the highest I've gone with H4895 with the 500s and 450s is 82 grains. I'm sure I could use another grain by slightly more compression.

That would move the 500s close to 2350 fps and the 450 TSX close to 2450 fps. All that from a 24" Ruger #1 barrel.

Yet, I did discover on June 30, 2008 with my CZ550 (25") that 80 grains of H335 gave 2249 fps (corrected to MV) from the 500 Hornady, whereas 80 grains H4895 gave a corrected average to MV of 2286 fps from the 500 Hornady. COL was 3.53", WLRM primers. Win brass used for the H335 load and Rem brass for the H4895. I'm sure that made little difference, if any. Temp was +20*C.

One week later (July 7, 2008), I fired two more 500 Hornadys but increased the H4895 by 1-grain to 81 grains, all else the same, temp at +25*C (77*F) and recorded MV was less by 4 fps at 2282 fps (corrected).

I doubt in reality that the July 7 firing was actually less, but there are anomalies that show up in the use of any chronograph. That has been recognized by experts in this field of research and study. No matter the cost, all will show slight differences from one lot of home-made ammo to the next that is supposedly "identical". So it's wise to test the same loads on a variety of occasions. Take the average of those if they are still hitting the target in the same group as previously. I've done this by shooting one bullet per week over several weeks from the same rifle and load.

Back to the original point: Generally I've found that H4895 can be compressed to any reasonable degree without degradation of results. But H335 (ball powder) is one of the best to a point, beyond which MV doesn't improve. Yet results didn't "fall apart" either. Generally, from my original lot of AA2230, pressures increase dramatically beyond a top safe load, whereas H335 doesn't do that in my experience. I've gone to 83 grains H335 under the 500 Hornady and there were no signs of undo pressure, but MV increased very little, if any, over 80 grains (using WLRM primers).

Another feature of probable interest: on the same date (July 7/08), I fired three, 350 TSX's over 81 grains RL-7, WLRM primers, Win brass (that was before I switched to H4198 permanently). The first shot registered 2703 instrumental. I then used a Bore Snake through the barrel for two pulls. The next two shots recorded: 2675 and 2677. There had been some copper buildup. So, such matters affect instrumental results. Accuracy wasn't an issue that prompted running the Bore Snake a couple of times, just the "feeling" that it should be done.

H4895

Bob
www.bigbores.ca

quote:

Originally posted by .458 Only:
I too have found H4895 best for compressed loads of the 450 TSX and 500s (Hornady and Speer - not the 500 TSX as I don't have the latter anyway.)
The only apparent exception is using 84 grns H335 under the 450 AF. But the highest I've gone with H4895 with the 500s and 450s is 82 grains. I'm sure I could use another grain by slightly more compression ...
H4895
Bob
www.bigbores.ca

Buy a donkey, Bob.
Still looking good for H4895 for those bravehearts who can handload !
AA-2230 might still be tops for those wanting to use a ball powder and non-compressed load, whether SAAMI COL or LongCOL.
I know H335 is good too but might be more temperature sensitive and is not needed if you have AA-2230.

About the cliffhanger from P3 of "Bear Bullets" at Bob's blog,
400-ish-pound black bear shot with "200-gr Barnes-X (prior to the TSX’s) at 2850 fps from the 22″ barrel of the .35 Whelen ..."
P4: Mystery solved.
Good read.
.458 WINCHESTER MAGNUM PERFECTION

Non Illegitimi Carborundum

I have loaded some cast bullets (401-grainers) with 65.0 through 69.0 grains of H4895 and a single 0.4" tall 0.5" diameter foam rod filler wad.

Same bullets were also loaded with 43.0 through 45.0 grains of AA/XMP-5744 with a stack of 4 of the above wads

WLR (not magnum) primer, 3.300" COL, and WW brass for all loads above.
Expecting 1900-2000 fps with the H4895,
and 1800-1900 fps with the AA-5744,
with pressures topping out around 30,000 PSI for both powders.



Switching from impulse to warp drive,
.458 WIN+P, 400-gr Woodleigh PP SN COL 3.425"
WW brass and WLRM primer for the low end of the workup,
Hornady brass and F-215 primer for the top end.
That is the end of my prepped&primed brass until I do another batch of it.
1-grain charge increments from 76.0 through 87.0 grains of H4895.
3 shots each charge from 76.0 through 81.0 grains in WW brass.
At 82.0 grains there are 4 shots, 2 shots with WW brass and 2 shots with Hornady brass.
Then finishing up with 3 shots each charge from 83.0 grains through 87.0 grains with Hornady brass.

Using a drop tube, 79 grains is a 100% fill with this shallow seating depth of 0.230".
87 grains is a dropped-tubed 110% fill.
Case is filled to top then seating of bullet compresses the powder, followed by
a hurry up to put a Lee Factory Crimp on it before the bullet pops out of the case.

The powder compression would be the same if the .458 Lott used same bullet crimped on the factory cannelure with 2.8" brass.
And pressure would be higher in the .458 Lott.

Numerology: 1,2,3 types of loads pictured above, and the powder charge maximums use the rest of the numerals 4, 5, 6, 7, 8, 9.
Zero is there too.
Zero is the amount by which the .458 Lott beats the .458 WIN+P.
This is quite auspicious, according to the numerologists.
Numerology is serious business to the Lottites, and this will surely get them to quaking in their boots.
The Lottites also worship Homer Simpson.
.458 WINCHESTER MAGNUM PERFECTION

Non Illegitimi Carborundum

Time has been limited lately here with lots of action at work, so my R&D had to slow down a little. Forward progress continues, however, with the first dozen live ".458 Win+P Torpedo" cartridges being loaded. I'm starting with H335 for now, and starting quite light at 68 grains and going up to 74.

Please ignore the box behind the rounds, as I am also playing with some Lehighs in the .50 BMG as well right now.

The Maz,

That is beauteous and fantastical. Buy a donkey for THE MISSION.

I got out to my home on the range yesterday.

The cast bullets need more work.
The AA-5744 loads (with a heap of filler) showed accuracy got worse as charge increased,
even if extreme spread of velocity improved.
The H4895 with a wee bit of filler showed accuracy improved as velocity increased,
though ES was not so good.

Must mean the AA-5744 pressure was greater than the H4895 pressure,
and H4895 does not burn efficiently at low pressure
but AA-5744 is a very efficient burner at about 30Kpsi and higher.

I reckon I need to try a lesser charge of AA-5744,
and a greater charge of H4895 with the 400-ish-grain cast bullets and filler (+/-).
And use my hardest bullets.





Alderella was shot in the "drop-in" Zytel stock,
but needs to go back into the glass-bedded HS Precision stock,
so as to be fair to the cast bullets.

quote:

Originally posted by The Maz:
Time has been limited lately here with lots of action at work, so my R&D had to slow down a little. Forward progress continues, however, with the first dozen live ".458 Win+P Torpedo" cartridges being loaded. I'm starting with H335 for now, and starting quite light at 68 grains and going up to 74.

Please ignore the box behind the rounds, as I am also playing with some Lehighs in the .50 BMG as well right now.

Those bullets would sure take a long time to come to a stop

Be interesting in a 460.

Meanwhile, 400-gr Woodleigh bullet in Bobbarrella, also with 25" Shilen barrel of 1:14" twist, glass-bedded B&C stock, and with 6X Leupold in "custom mounts,"
same day and 87*F,
has been perfected.
It just got more accurate as charge increased all the way up to 87.0 grains of H4895.
Extreme Spread of 3-shot groups was only 3 fps for both the 86.0-grain and 87.0-grain charges.




.458 WINCHESTER MAGNUM PERFECTION

Non Illegitimi Carborundum

quote:

Originally posted by Mike McGuire:

quote:

Originally posted by The Maz:
Time has been limited lately here with lots of action at work, so my R&D had to slow down a little. Forward progress continues, however, with the first dozen live ".458 Win+P Torpedo" cartridges being loaded. I'm starting with H335 for now, and starting quite light at 68 grains and going up to 74.

Please ignore the box behind the rounds, as I am also playing with some Lehighs in the .50 BMG as well right now.

Those bullets would sure take a long time to come to a stop

Be interesting in a 460.

I'm not so sure that they would be quite so slow to stop. They are LONG and base-heavy, and will certainly turn sideways when penetrating any animal. Hydrostatic shock might well exceed a hollow point.

They are only useful in a single shot as they are too long to load to feed from a magazine, even in a .460.

quote:

Originally posted by RIP:
Meanwhile, 400-gr Woodleigh bullet in Bobbarrella, also with 25" Shilen barrel of 1:14" twist, glass-bedded B&C stock, and with 6X Leupold in "custom mounts,"
same day and 87*F,
has been perfected.
It just got more accurate as charge increased all the way up to 87.0 grains of H4895.
Extreme Spread of 3-shot groups was only 3 fps for both the 86.0-grain and 87.0-grain charges.




.458 WINCHESTER MAGNUM PERFECTION

Non Illegitimi Carborundum

RIP,

I modeled your load in QL just for grins, and here is what the software kicked out.



Pressure is likely a little above specs, but then again QL isn't the greatest at predicting .458 pressures due to the throat design. Velocity was pretty close, about as well as I would expect a computer program to get.

That is about the definition of a "+P" load!

The Maz,

You did not bother to get the COL correct on that (should be 3.425" not 3.343"), but I know it was just for yucks.
Yes, QuickLOAD is hopeless with the .458 Winchester Magnum throat.

That load is just a maximum .458 Lott load from the Woodleigh manual, by gosh.
Seat the 400-grain PP SN in a 2.8" case and crimp on the primary cannelure at 3.425" COL.
Should be </= .458 Lott MAP according to Woodleigh.
Powder compression should be the same in the .458 Lott.
Pressure will be higher in the .458 Lott than in the .458 WIN+P,
since the SAAMI .458 Win.Mag. throat is longer, absolutely.
There is more room for free-travel into the funnel of the throat with the .458 WIN than with the .458 Lott, when both loads have the same COL.

Physics does not lie, as the Lottites like to say, though they will conveniently neglect the physics if it does not suit their agenda.

And do not believe the baloney about excessive free travel causing inaccuracy in the .458 WIN.
See 0.54 MOA 3-shot bughole group,
done with Woodleigh 400-grainer and 87.0 grains of H4895 for +6000 ft-lbs Muzzle Energy.


Physics does not lie.

.458 WINCHESTER MAGNUM PERFECTION

Non Illegitimi Carborundum

Nice group.
You shoot pretty well for a bearded hillbilly!

quote:

Originally posted by crshelton:
Nice group.
You shoot pretty well for a bearded hillbilly!

CRSHELTON,

Buy a donkey for those flowers, nicest compliment ever.
Some credit does go to Bobbarrella Shilen-CZ's set trigger:


I do trim my beard pretty regularly whenever the hairs cover my pie hole too much.
Twice a year I get out the dog clippers and take it down to 0.458" hair length all over face and head.
Jan. 1, "New Hairs Day"
and
July 4, "Independence from Hair Day."

.458 WINCHESTER MAGNUM PERFECTION

Non Illegitimi Carborundum

Another factor for good accuracy with Woodleigh SN bullets: Foul the barrel with 34 Woodleigh SN bullets before shooting a group for accuracy.
If group is good, go on safari.
Clean the rifle barrel while on safari by firing the rifle at least once daily.
Cleaning is not necessary for the day if one or more one-shot kills have been made that day.
Caressing the exterior of the rifle with oiled and dry cloths is permissible ad lib.
Perfect for this is one of Craig Boddington's souvenir-soiled T-shirts, may bring good luck if not so badly soiled that the scent spooks game.
.458 WINCHESTER MAGNUM PERFECTION

Non Illegitimi Carborundum

Thank the .458 Winchester Magnum for giving Art Alphin inspiration to create A-Square.
After his first safari in 1974, due to supposed shortcomings of the .458 Winchester Magnum, Art necked up the .460 WBY to .510-caliber.
Yes, Art rustled up the .500 Buhmiller wildcat and rebranded it to .500 A-Square, circa 1975-1976.
Same excuse as for Jack Lott's wildcat rustling of the .450 Watts Magnum:
The mighty .458 Winchester Magnum is the most inspirational cartridge ever.
This bit of trivia was brought to you for purposes of THE MISSION.
.458 WINCHESTER MAGNUM PERFECTION

Non Illegitimi Carborundum

John Buhmiller. An interesting pioneer. I have a buddy with a Buhmiller rifle. Nice old Mauser 270.

quote:

Originally posted by Fury01:
John Buhmiller. An interesting pioneer. I have a buddy with a Buhmiller rifle. Nice old Mauser 270.

Uncle John always carried a .458 Win.Mag. as a backup on his safaris with his many big-bore wildcats.
IIRC, Buhmiller said he killed much game of all types, including elephant culling, with the .458 WIN.
Found it, worth repeating, for THE MISSION:


.458 WINCHESTER MAGNUM PERFECTION

Non Illegitimi Carborundum

Factoid:

A fired .458 Win.Mag case by Winchester (WW Super)
measures 2.491" long and will hold 88.8 grains of H4895 dumped in and leveled at case mouth with a straight edge.

Full-Length size that case with an RCBS FL sizer die and the case grows to 2.502".
Now it will hold only 83.3 grains of H4895 administered as above.

Using a drop tube, I can get 87.0 grains of H4895 into the FL-sized case, and be just short of overflow.
My aluminum arrow shaft drop tube (~26" long) allows me to gain about 4 grains of H4895 capacity.

Been thinking that the 400-grain Woodleigh PP SN should not go much faster than 2500 fps MV due to the maximum impact velocity of 2500 fps recommended.
You never know when you might have to shoot something at spitting distance.

So, in Bobbarella Shilen-CZ with 25" barrel:
82.0 grains of H4895 (mildly compressed with drop tube use) >>> 2505 fps
78.5 grains of AA-2230 (not compressed, not drop-tubed) >>> 2505 fps.
That's a minor God wink.
.458 WINCHESTER MAGNUM PERFECTION

Non Illegitimi Carborundum

And really now, 6000 ft-lbs with a monometal copper .458/ 400-grainer is quite sufficient for any soft-point work, and then some:
2600 fps 400-grainer = 6004 ft-lbs

That might be done with the BBM T6 .458/ 400-grainer,
and compressed H4895,
somewhere short of 87.0 grains.


L to R above:
1. 400-gr T6
2. 400-gr Woodleigh
3. 407-gr 92-5-2-1
4. 411-gr Linotype

86.0 grains makes the Woodleigh PP SN .458/ 400-grainer (#2 above) go 2603 fps, with an extreme velocity spread of only 3 fps for 3 shots.

COLs with that 400-gr T6 (#1 above) might be: 3.300", 3.420", 3.540", and 3.660",
firmly crimped on a compressed charge of H4895.
2600 fps might require the longest COL,
longer than a .458 Lott.
But maybe not.
I will be rooting for the 3.540" COL.
.458 WINCHESTER MAGNUM PERFECTION

Non Illegitimi Carborundum

I still think RIP’s work with long throat 458 WM should be published in a book.

LHeym500,

Buy a donkey for that posey, and for turning the page to 206.

I want an accurate 400-ish-grain plinker and game getter at 1800 to 2300 fps in the .458 WIN.
Easier on the shoulder AND cheaper on the manpurse.
That is very easy to do with .45-70 jacketed bullets, but not as much fun and not as cheap as making your own cast bullets do it.

The 407-grainer of BHN 25 is next up, and 3.270" COL would make a prettier "light crimp" location in its bottom groove.

AA-2495, though lacking in temperature insensitivity, is an extruded powder that (in comparison to H4895) might give:
slightly increased fill
lower pressure for higher velocity
increased ballistic efficiency and
increased percentage of propellant burnt,
for the low-pressure loads desired.

Yes, I have resurrected my old version of QuickLOAD,
useful for making relative comparisons,
worthless for pressure and velocity values in the .458 Winchester Magnum.
Throat effects are unknowable to QuickLOAD, same as to a Lottite.
The .458 WIN gives higher velocities and lower pressures than it predicts.

I want to try 39.0 to 42.0 grains of AA-5744 with filler
and 67 to 71 grains of AA-2495 and H4895
with the 407-grain hardcast, gas-checked, PC-painted boolit at 3.270" COL.

No problems noted with filler and 60% loads of AA-5744. I will be using less than 60% next time,
for less than 32,000 PSI predicted by QuickLOAD.
Since it is a .458 WIN, that is a safe guess, since QuickLOAD over-estimates pressure.

I once feared AA-5744 with filler had "ringed" a chamber.
I reckon, that factory rifle chamber had been "ringed" at the factory, and I never paid attention to the brass in my grasshopper days.
Thus happened the reaming of a .458 WIN Whitworth to .458 WinRuger.
.458 WINCHESTER MAGNUM PERFECTION

Non Illegitimi Carborundum

My personal theory regarding the 458 Win throat is that it is nearly uniquely designed as a long and shallow funnel. Most freebore designs don't have a long taper, just a longer groove diameter on-ramp before hitting the rifling, whereas the 458 Win has a 0 degree 29 minute funnel. What makes it so interesting is that the end closest to the case is so large that it causes a lot of gas to go past the bullet.

I believe that this creates a very high pressure and density fluid "gas throat" that guides the bullet straight into the rifling, while lowering initial pressures by quite a bit.

When the base of the bullet clears the case, the gasses have to rush into the funnel at full pressure, and gasses at that pressure are more like a thick plastic density-wise than air, and pressure differences almost instantly get equalized. Think of a fluid bearing and you get the idea. Or a momentary "gas sabot" effect.

Basically, the powder gasses fill the funnel and force the bullet to go straight.

quote:

Originally posted by The Maz:

Most freebore designs don't have a long taper, just a longer groove diameter on-ramp before hitting the rifling,

I have always been under the impression that a parallel freebore was a Weatherby deal and the specification diameter being .0005 over bullet size or groove diameter.

Lore for THE MISSION, worth repeating:

quote:

Originally posted by The Maz:
My personal theory regarding the 458 Win throat is that it is nearly uniquely designed as a long and shallow funnel.



Most freebore designs don't have a long taper, just a longer groove diameter

Look to the SAAMI .458 Lott throat for the modern typical throat,
0.001" greater diameter than groove diameter for the short length of the parallel-sided free-bore, only 0.178" long.
Then an abrupt leade of 2-degree hemi-angle, or 4-degree cone-angle of leade.
This ends at bore diameter in the rifling, which is 3.129" from breech face of chamber.
The corresponding length of chamber for the SAAMI .458 Winchester Magnum is 3.642".
Thus, the power of the .458 WIN+P dwarfs the SAAMI .458 Lott.


on-ramp before hitting the rifling, whereas the 458 Win has a 0 degree 29 minute funnel.

More precisely, a leade-only throat with 0* 29' 30" hemi-angle. No parallel-sided freebore.
So the cone angle of the leade is 0* 59', just one minute of angle less than one degree.
That keeps it tight. No sloppy 1-degree cone angle of leade allowed if throat is to be at tight minimum spec.

What makes it so interesting is that the end closest to the case is so large

YES INDEED ! 0.469" diameter is the diameter of the base of the leade cone.
The chamber neck ends at 0.483" diameter at a distance of 2.520" from breech face,
then tapers down at a 45-degree angle into the base of the leade.
0.469" is 0.011" greater than bore diameter at the base of the leade,
0.010" greater than SAAMI maximum bullet diameter of .459" for jacketed bullets !

that it causes a lot of gas to go past the bullet.

NOW YOU ARE DOING SOME GREAT THINKING:

I believe that this creates a very high pressure and density fluid "gas throat" that guides the bullet straight into the rifling, while lowering initial pressures by quite a bit.

A gas and igniting propellant solids "surge" jumps forward into an effectively larger chamber as soon as the bullet starts moving.
Surely the start-pressure would be greatly reduced by the free-travel before rifling is fully engaged.
The fire-surge of gas and solids is engulfing base of bullet in the base of the leade cone of throat.

When the base of the bullet clears the case, the gasses have to rush into the funnel at full pressure, and gasses at that pressure are more like a thick plastic density-wise than air, and pressure differences almost instantly get equalized. Think of a fluid bearing and you get the idea. Or a momentary "gas sabot" effect.

GREAT THOUGHT ! Igniting solids and gas might produce a fluid-mechanical-dynamic stabilization of the base of the bullet.
The "GAS-SOLID-SABOT" would be more appropriate than "GAS SABOT."

Basically, the powder gasses fill the funnel and force the bullet to go straight.

Like a friendly little campfire built around the base of the bullet.
The FIRE SABOT consumes itself as soon as it has guided the bullet into the rifling so perfectly.
Very good.
The Lottites will hate to hear that.

.458 WINCHESTER MAGNUM PERFECTION

Non Illegitimi Carborundum