IMR SR 4759 seems to be an on-again, off-again, on-again powder.
Here to stay, hopefully like AA-5744.

Found an old 1999 HANDLOADER'S GUIDE for IMR.
Below are two maximal loads for 510-grain bullet.
They recommend reducing by 10% and increasing "as pressure indications permit."

.458 WINCHESTER MAGNUM
WIN. CASE; WIN. 8-1/2-120 PR
WIN. 510 GR. SP .457" DIA.
25" BBL.; 3.340" C.O.L.

SR 4759 44.5 grains >>> 1645 fps <<< 52,400 CUP

IMR 4227 45.0 grains >>> 1665 fps <<< 52,700 CUP

Old data, old pressure units.
IIRC, 53,000 CUP is maximum for .458 Win.Mag.,
supposedly equivalent to 60,000 psi SAAMI MAP now.
Maybe a typo on the bullet diameter?
SAAMI spec is .459" maximum diameter for jacketed bullets,
and .458" minimum diameter for barrel grooves, so .457" bullet in a .459"-grooved barrel is "in spec."
Maybe an old Winchester gimmick to use .457" diameter bullets ?

IMR SR 4759 is a bulky powder.
The 8-pound jug of it is huge!
Might not need much filler for ShortCOL, but I will use foam wads and LongCOL, and cast bullets.

Rip ...

Rip,
I have used from 30-39 of 4759 with 425, 433, and 485 grain cast bullets with Dacron Fiber filler. I did not chrono them but research said 1450 to 1775 fps. I also have a Max of IMR 4759 of 42 grains for both 405 and 500 grain lead in Re-loaders Reference.
I settled on 39 grains and it was a very good load. shot 1 big hole at 50 yards and 2-3" at 200 yards over sticks. 3.275" COL and 3.265" on the 485's.
And yup, 4759 is bulky. I use the Lee Scoops number 230 heaped to get my 39 grains.

Buy a donkey, Fury01.

IMR quit making that SR-4759 about 5 years ago.
I bought my 8-pound jug of it in 2014, last batch, I guess, haven't used any yet.
It is time.
They quit last century too but brought it back for a while.
The bulk comes from the hollow core of each short and fat cylindrical, extruded granule.
The closest thing to it might be Western Powders (Accurate Arms) Blackhorn 209, the BP substitute !

I cracked open my jug of IMR-SR-4759 for the first time, filled a W-W .458 WIN case to overflowing and leveled it off with a notecard.
Same for a few other powders.

Here are weights of powders for a 100% gross fill:

Blackhorn 209: 63.6 grains ... hollow, shortcut, tubular/extruded

IMR-SR-4759: 66.5 grains ... hollow, shortcut, tubular/extruded, larger length and diameter tubes externally, with smaller hollow centrally than Blackhorn 209

IMR-4227: 85.4 grains ... tiny extruded cylinders

AA-5744: 88.3 grains ... not so tiny extruded cylinders

AA-2460: 89.6 grains ... ball powder looking very uniformly spherical

AA-2230: 94.1 grains ... ball powder with many flattened granules, hardly spherical, greater surface area for volume, burns faster, lesser volume for weight

Blackhorn 209 is supposed to be a clean-burning substitute for black powder.
Might be a substitute for IMR-SR-4759 too.

Let us say that IMR 4227 works in a load at 78% loading ratio, volumetric fill of net case capacity.

The same weight of SR-4759 would be a 100% fill.
No filler needed, similar burn rate.

Maybe Blackhorn 209 will be even better at filling a case for a reduced load in the .458 WIN.
100% or mildly compressed loads go even slower than a 100% load of SR-4759.
Pretend BP too.

Rip ...

Old NRA pub by William C. Davis, Jr. HANDLOADING, 1981
shows loads for .458 WinMag with 400-gr FN Speer-Jacketed
WIN case, CCI 200 primer, 24" barrel, COL </= 3.340"
DUPONT 4759
26.0 gr >>> 1262 fps
28.0 gr >>> 1338 fps
30.0 gr >>> 1445 fps

No pressures given, old standard then was 53,000 CUP for SAAMI MAP. Above loads must be below 28,000 CUP ...

Rip ...

SR-4759 data in 50th Ed. (2016) of LYMAN Reloading Handbook

.458 WinMag with Hornady 500-gr RNSP-Jacketed
WIN case, WLR primer, 24" barrel, COL 3.340"
SR-4759
30.0 gr >>> 1216 fps <<< 18,000 CUP
34.5 gr >>> 1384 fps <<< 25,200 CUP

.458 WinMag with Lyman 475-gr P/RN-GC (#2 Alloy) cast bullet (#457671)
WIN case, WLR primer, 24" barrel, COL 3.145"
SR-4759
29.0 gr >>> 1428 fps
35.0 gr >>> 1646 fps

RCBS CAST BULLET MANUAL number 1 (1986)

.458 Winchester Magnum with 425-gr RCBS 45-405 FN-GC cast bullet (soft lead), grease lubed
W-W case, CCI 200 primer, 24" barrel, COL unspecified, no pressures reported
SR-4759
38.0 gr >>> 1686 fps
42.0 gr >>> 1872 fps

.458 Winchester Magnum with 507-gr RCBS 45-500 FN-GC cast bullet (hard alloy), grease lubed
W-W case, CCI 200 primer, 24" barrel, COL unspecified, no pressures reported
SR-4759
40.0 gr >>> 1566 fps
42.0 gr >>> 1659 fps

Blackhorn 209 loads for BPCR, any of these can be used in the .458 WIN with variable COL, for some nice reduced loads,
if the powder will fit in the case and the bullet will fit in the throat.
Use filler for any air space,
use compression if needed,
with the caveat that 63.6 grains of Blackhorn 209 will fill a .458 WIN case to the top if poured in with no drop tube.
A drop tube will allow more powder to compress.
Those hollow grains ought to compress easily.





The WESTERN POWDERS HANDLOADING GUIDE Edition 1 shows the same loads as above.
They give no starting load, just the maximum loads above.
But that book also gives the COL associated with each load above.

All of the above Blackhorn 209 velocities are for 29" barrels.
No worries, the .458 WIN with shorter barrel might even surpass those velocities,
with full-case/compressed loads of Blackhorn 209.
Definitely so with the other powders for "reduced loads."

The maximum COL for the .45-100 Sharps Straight is 3.380" with 570-grain cast bullet and 41.5 grains of Blackhorn 209.
This is the .45-2.6", only 2 grains of water bigger than the .458 WIN 2.5".

The maximum COL for the .45-110 Sharps Straight is 3.650" with 570-grain cast bullet and 49.0 grains of Blackhorn 209.
Seating to 3.600" will produce only slightly higher pressure and velocity, easily within the capability of the .458 WIN bolt action.
Move over Quigley.

The maximum COL for the .45-120 Sharps Straight is 4.020"" with 570-grain cast bullet and 51.0 grains of Blackhorn 209.
This much powder and a COL of only 3.600" in the .458 WIN with 570-grain bullet ought to put the 3-1/4"-cased pretender to shame.

Rip ...

Waters pet loads commented that 4759 and 4227 were both good cast choices in lots of cartridges but waters preferred 4227. I bought 24 lbs of 4795 when it was discontinued at Powder valley. I thus have enough for 458wm, 35 whelen and good old -06 use with cast for a long time.
As I have mentioned before I also use aa2015 in the 458wm and like it a lot. I’ll be killing a doe on New Year’s Day with that behind a 485 cast.

RIP:

I also have that HANDLOADING publication of the NRA (1981). There's an interesting note about pressure: "The established maximum product average for factory ammunition is 56, 200 c.u.p."

They do acknowledge that the cartridge "is commonly limited to about 53,000 c.u.p."

"COMMONLY limited" to "ABOUT". I've quoted that, or referred to it in my former reloading manual on the .458 Win Mag. There's more than a strong hint there of the liberty employed by factories in the judgement of "safe" or appropriate pressure in the attainment of their goals through available commercial powders of the day. Yes, they did mix them at times.

So, the assumption, that WW 748 was the "culprit" is not the whole, or honest opinion as to any failures to attain the .458 WIN's declared or real potential.

If we check Winchester's own results from that powder, we see why the results obtained were so far from its real potential = 24" barrel:

500gr WIN FMJ; COL = 3.34"; 73 grains 748 = 2040 fps @ 39,000 CUP
510gr WIN SP; COL = 3.34"; 75 grains 748 = 2065 fps @ 41,000 CUP

When Accurate powders were first published (before owned by Western), they gave results in CUP. When their second edition came out they published the same data but changed pressure to PSI.

I calculated how they did that, and they simply multiplied CUP by 1.18 = PSI in every load for the .458 Win Mag.

Examples for the 500gr Hornady RN:

2015 BR @ 68 grains (max) = 2149 fps @ 49,200 cup (58, 056 psi)
2230 @ 72 grains (max) = 2159 fps @ 45,600 cup (53,808 psi)
2460 @ 74 grains (max) = 2192 fps @ 44,800 cup (52,864 psi)

The CUP I've copied from their No.1 Loading Guide.
Those in brackets are the numbers now published from the same load data. So, multiply or divide by 1.18, as the case may be.

If that be true (as I stated in my former manual on the .458 Winchester Magnum), then Winchester was only loading their ammo to about (average) 40, 000 CUP! ... or 40, 000 x 1.18 = 47, 200 PS! !!!!!!!

Little wonder that those results have defamed the magnificant .458 WIN !!!

And others have followed their lead!

And still others have been "happy" to use that kind of underloading of the .458 WIN to further discredit its performance, and proclaim "We needed the Lott!"

BUT! If the NRA publication is correct that the "established maximum average for factory ammunition is 56,200 CUP", what is that in PSI?

Maybe... 56,000 x 1.18 = 66, 316 PSI !!! That's "peak" or "max" - that is NO load should exceed that, not as some proclaim that
absolute max is MAP -- which is "maximum AVERAGE pressure. And if MAP is 53,000 CUP, then that translates to 62,540 PSI -- the same as the LOTT !!!!!!!!!!

Someone, OR quite a few have been distorting REALITY about the GREAT .458 Winchester Magnum! Why?

Thanks RIP for putting the record where it should be -- and should have been!

Bob
www.bigbores.ca

Shot the Ruger No.1 today at the farm with the following 5 shot result:
78.0gr. RL-15
505gr. bullet from Accurate mold 46-500L2
WW brass, CCI250 primer
velocity= 2185 fps (chrony 15ft. away)

78gr. of RL-15 powder required seating the bullet out .080" more than optimum so instead of .460" of bullet in the case and using the crimp groove, it ended up being .380" bullet shank in the case. Although velocity and accuracy was good it would be too much powder for the case with a Hornady 500gr. RN to be able to use the crimp cannelure. All of my powder testing is based off using the available powder space when a Hornady 500gr. RN is seated to the factory cannelure so 78.0gr. of RL-15 is just too bulky.

Bob,

It is a bit disappointing to think of pressure values derived by a linear correlation of PSI to CUP.

But as Alf's graph shows, it is not that bad if defined for specific pressure ranges using different correlations.



Up to about 30,000 PSI the CUP are close to identical.
I recall seeing some old standards for .45-70 Govt. where the CUP and PSI were the same for MAP,
28,000 in either units.

Above 30,000 PSI the CUP curve goes off in a parabola like the trajectory of a bullet, PSI remains a straight line like a laser beam.

Between 40,000 PSI and 60,000 PSI,
a linear approximation for CUP is less bad than for pressures over 60,000.
From 40,000 PSI to 60,000 PSI, the approximation of CUP X 1.18 = PSI ain't that bad.

As it is, it seems CUP of only 3 significant digits was converted to PSI of 5 significant digits by use of 3 significant digits multiplier.
Pressure to the nearest 100 CUP should have been converted to nearest 100 PSI, rounded off.

Rip ...

quote:

Originally posted by admiral:
Shot the Ruger No.1 today at the farm with the following 5 shot result:
78.0gr. RL-15
505gr. bullet from Accurate mold 46-500L2
WW brass, CCI250 primer
velocity= 2185 fps (chrony 15ft. away)

Excellent.

78gr. of RL-15 powder required seating the bullet out .080" more than optimum so instead of .460" of bullet in the case and using the crimp groove, it ended up being .380" bullet shank in the case.

Excellent.

Although velocity and accuracy was good it would be too much powder for the case with a Hornady 500gr. RN to be able to use the crimp cannelure. All of my powder testing is based off using the available powder space when a Hornady 500gr. RN is seated to the factory cannelure so 78.0gr. of RL-15 is just too bulky.

Great!
COL: I like them all.
The SAAMI .458 Winchester Magnum with "Variable COL" might be called the ".458 WIN-V."
V for variable and V for VICTORY over the .458 Lott.

AA-2230 and AA-2460 are better choices for top velocity with no compression, if you ever run out of RL-15.

As quoted by Bob:

Examples for the 500gr Hornady RN:

2015 BR @ 68 grains (max) = 2149 fps @ 49,200 cup (58, 056 psi)
2230 @ 72 grains (max) = 2159 fps @ 45,600 cup (53,808 psi)
2460 @ 74 grains (max) = 2192 fps @ 44,800 cup (52,864 psi)

Those are for 24" barrels, COL is 3.305" with the 500-gr RNSP Hornady, and no compression of powder.
Both AA-2230 and AA-2460 are claimed to have excellent ThermoBallisticIndependence.
RL-15 ain't bad, just not as good,
and there seems to be quite a bit of lot-to-lot variability with RL-15.

Rip ...

quote:

Originally posted by Fury01:
Waters pet loads commented that 4759 and 4227 were both good cast choices in lots of cartridges but waters preferred 4227. I bought 24 lbs of 4795 when it was discontinued at Powder valley. I thus have enough for 458wm, 35 whelen and good old -06 use with cast for a long time.
As I have mentioned before I also use aa2015 in the 458wm and like it a lot. I’ll be killing a doe on New Year’s Day with that behind a 485 cast.

I hope you got a good price on that 4759.
Blackhorn 209 is expensive !
It can be found at the local Walmart for less than $40 per 10 oz. in the muzzleloader section,
close to $45 per 10 oz. at "boutiques" where the "toilet-water-scented" people shop.

MidwayUSA has it for $34.99/10-oz ($3.50/oz)
and $242.99/5-lbs jug ($3.04/oz).
The fluffiness of the powder makes for smaller weights in same size jugs.

https://www.midwayusa.com/product/2649173432

Good ol' IMR-SR-4759 came as 8 pounds in a huge jug.

Rip ...

I bought it a few years back. If Memory serves I paid Under a $100 per jug.
You can buy Buffalo Rifle powder from Shooters world for $161 I think.

quote:

I recall seeing some old standards for .45-70 Govt. where the CUP and PSI were the same for MAP,
28,000 in either units.

Yep, I have that report somewhere; ran across it recently looking for somethings else.

OK, I found it.

"Correlating PSI and CUP" by Denton Bramwell.

This paper is six pages long and you can find it by searching on the title above. It includes tables and graphs of the subject matter.
Enjoy!

crshelton,

Got it:

https://www.shootingsoftware.c...p/psicuparticle2.pdf

Buy a buy a donkey for THE MISSION.

Rip ...

Marcella fired her first 6 shots at paper today.
Chronograph was at 5 yards, targets were at 50 yards.
Iron sights only.

We are happy to inform THE MISSIONARIES that she was on paper with no fiddling.
J-B-Welded front ramp, little white CZ front bead from NECG (found in sight parts box by a whim),
and the old original NECG peep sight for Weaver base.

3 shots of Hornady factory .458 Winchester Magnum 500-gr DGX landed roughly 3" to the left and 3" high at 50 yards.
I am wondering if the newer NECG "ghost ring" peep will work, since it has a lower maximum height adjustment.
Maybe.
I am sure the current "whimsical" sights can be zeroed as is, since there is plenty of down adjustment and windage adjustment of the peep,
not to mention the front sight height, by ordering a new insert.
A low patridge with the ghost ring might be sweetest of all.

And there was no punishment of my face, only punishment of my shoulder. Invigorating !
Marcella's stock is fine for MY FACE with iron sights.

The 400-gr GSC HV landed about 7" high and 4" to left with same sighting, no adjustment, 50-yard target again:



That was the last 3 rounds of the ammo I loaded and shot 14 months ago and coincidentally temperature was same 55 degrees F today.
It was colder last month when I used one of those bullets on a doe, but it still worked fine.

So this is a pretty good comparison of two barrels, both at 55*F ambient, and same ammo:

.458 WIN-V 3.395" COL 400-gr HV, same ammo batch fired in both barrels:

Shilen 25", Medium Varmint (#5.5 sporter), stainless, 6-groove, 1:14" twist, 0.459" groove diameter: 2527 fps MV

McGowen 23", #4 sporter, stainless, 6-groove, 1:14" twist, 0.458" groove diameter: 2511 fps MV

The previous target shot at 100 yards with Alderella Shilen-Ruger's 25" barrel and a Nikon scope, 14 months ago:



Rip ...

Marcella would prefer her iron sights zeroed for 480-grainers at 2150 to 2200 fps,
the factory 500-grainers at 2125 fps should be close enough with that setup.
Then all the lighter bullets can each get their own scope setting for zero.

Merry Christmas and



Rip ...

That's pretty great RIP. !
Little bit taller front sight insert and you will be dinging the door bell.
Good to know that the factory ammo is producing adequate velocity.

We also had a terrific night sky on the first night of the Festival of Lights Rip. Thanks for sharing the view of yours! May your lamp never run out of Oil Sir.

I'm aware of all the confusion over the relationship of CUP to PSI. I've known as far back as my first .45-70 that 28,000cup was about 28,000 psi. That's not exactly news to me.

However, while some manuals now provide some results in psi, they still give some older results in cup. Moreover, all say something to this effect: "If there are 'signs' of excess pressure, reduce the load by a couple of grains". And that's assuming someone is using their max load. So, it's still left to the discretion of the handloader as to whether there are "signs" of excess pressure, whatever that may mean short of blowing up a rifle or self!

I, of course, didn't write the NRA manual of 1981, nor the Accurate manuals that simply multiplied CUP by 1.18 to tell us that they were actually getting CUP X 1.18 translated to PSI. Has anyone here trusted the declared results of Accurate powders(Western)in PSI? They were not tested in piezo, but translated from CUP.

ALF: I've read your wisdom, as I have a multitude of other current day "experts", and frankly I don't trust, or put much weight on any of it as there remains too much contradiction and too many variables. I've talked in person with head ballisticians of a number of powder and bullet companies, and I've had the use of QuickLoad from a friend. In the end, I use my own judgement.

The loads published by Winchester, and reported in the Hodgdon manual, though in CUP, nonetheless indicate that Winchester seriously UNDERLOADED their ammo for the .458 Winchester Magnum.

True, we have the benefit of better scientific equipment and understanding of what that all means, but none of it can be taken for granted that "their results" with their equipment, and thinking, will have 100% meaning when applied to our store-bought rifles -- so, again, I use my most informed judgement for the .458 WM and any other rifles I've owned for which I developed handloads. And, as to the .458 WM, my loads, that were formerly ridiculed, have been more than justified here, but also exceeded in RIP's testing without a single just negation. Thanks to RIP.

God's best blessings be to all of you at this Christmas season and throughout the New Year.

Bob
www.bigbores.ca

Thankfully Ernest saved Christmas in 1988, and even he gets it.
Alf is supporting the Western Powders Co. conversion of their old CUP data to PSI.



Rip ...

The Western Powders data is perfectly acceptable for the handloader.
Much a-doo-doo about nothing for those who think not.

Here is a start on some 480-gr .458 WIN-V cast bullet loads:

Goldie Ruger-Pedersoli (.45-2.6"-SWT) fired a load yesterday.
Accuracy good.
Velocity surprisingly high.
It was the .458"/464-gr Lyman PH bullet of 92-5-2-1 alloy, PC-painted, plain base, in the .457"-grooved, 1:18" twist.
MV was 2101 fps (G1 BC = 0.237).
Powder charge was 63.0 grains of AA-2460 with filler, F-215 primer, COL 3.525".

So, the .458 WIN-V could be loaded to 3.425" with same bullet, powder charge and filler, and primer, for similar velocity,
since the .458 WIN-V is only 2 grains of water less in gross case capacity, with same throat.

Instead, the .458 WIN-V will use 63.0 grains of AA-2460 (with filler) as a starting load for all cast bullets from 475 grains to 543 grains.
Velocities might be under 2100 fps to start, but will be worked up to approach 2200 fps,
in the 23"-McGowen-barreled rifle.

I will be needing to try that IMR-SR4759 for nostalgic, lower-velocity/gentler loads with cast bullets.
I dig IMR-4227 with filler too.

Fury01's suggestion of Buffalo Rifle powder, made by Lovex, is noted,
and also noted that it is said to be very similar to AA-5744.

Another note:
The .45-70 Govt in a 28"-barreled, .457"-grooved rifle with .458"/464-gr Lyman PH, all with W-W brass and WLR primer, and all with COL 2.555",
AA-2460 powder:
44.4 gr with filler (highly compressed foam wad) >>> MV 1710 fps MV (BC = 0.237) (ES of 23 fps for 5 shots)
46.0 gr with no filler (100% full) >>> 1751 fps MV (BC = 0.237): BETTER LOAD, more accurate, lesser extreme spread (14 fps for 5 shots)

Elmer would approve of a 464-grainer at +1700 fps from a .45-70 Govt.
Probably more so than a 400-grainer at 1800 fps.

Rip ...

Elmer was right on many things and did so when trial and error was the basis of most progress in things shooting. He would certainly approve of your work here Rip.

Fury01,

You are too kind.
I bet you and Elmer both would approve of this for Marcella:


Marcella has a 27.5" sight radius with her NECG Weaver peep, 23" barrel, and CZ ramp.
Numerologically amazing, she needed 0.0458" adjustment with right windage and 0.0458" down elevation on that rear sight,
easily done.

The front bead height is 0.285", to top of bead.
That 0.375"-tall gold (brass) patridge can easily be filed down by 0.100",
making it perfect for the factory 500-gr DGX load at 2125 fps.
There is plenty of elevation and windage left on the rear peep to adjust for the likes of the 400-grainer at 2511 fps.

The rear aperature is 0.125" diameter for field use, and the spare for sighting in at range is significantly smaller, 0.093" IRC.

The so-called ghost-ring version of the NECG Weaver peep is the sorriest one of the bunch, hardly a ghost ring,
and does not offer enough adjustment range for use on Marcella.
The Ruger and CZ ghost-ring peeps from NECG are excellent.
I prefer the standard NECG Weaver peep on Marcella.
In fact I am stuck with it and stuck on it !

We might also like this if I ever booger-up the slotted-head screws on Marcella:


She has the Connecticut-Classic, one-piece floorplate, only needs two of those screws.

Rip ...

The Perfect Front sight. I have a Solid Steel one on my 30-06 Mauser 98 that I found on some obscure sale somewhere. It fit a 3/8's dovetail and when I put the Weaver mount Peep on her, that great big tall square sight is right in front of my eye. The middle of anything of any size is still the middle. If your eye can see it clearly, your brain can calculate it clearly, so I can hit at any range I can resolve the target enough to put the center of the sight on. Love to have a Gold one indeed. Long range shooting with such sights, well maybe any Iron sight, contains a good measure of practiced trust in ones brain and trigger finger. Sharpsguy is the best example in our current conversations of this but Elmer would fit right in. You have to trust your sight picture enough to break a clean shot. Then the barrel, bullet and charge do the work.
Best to you Sir.

That's a nice sight, Ron, though I suspect a 45-degree sourdough might be even better in dim forests.

Happy Christmas and all appropriate complements of the season to everyone at the mission.

Paul,

Buy a donkey and Merry Christmas to the antipodes.
Hope it is not too hot down there.
We are even having a heatwave here, +60*F for X-mas !
Hopefully "climate change" brings us some ice age soon !
The sourdough sight is nice, my favorite bread too,
ever since I urinated in the Yukon River on the way to Alaska.
It will be interesting to see where 540-grainers at 1350 fps MV fall on the target in relation to the other .458 WIN-V loads.

Rip ...

quote:

Originally posted by RIP:

Merry Christmas and



Rip ...

Thank you, RIP.

You surely appreciate irony after the many pages pointing out inconsistencies in the way people have treated the 458WinMag.

And yes, Happy Hanukka (fourth candle today) and Merry Christmas.
How many are aware that Hanukka, celebrating the rededication of the temple, is celebrated by Jesus in the New Testament (John 10:22) but ironically is not part of the Hebrew Bible? Just another of life's smilies and God's smiles .

quote:

Originally posted by RIP:
Paul,

Buy a donkey and Merry Christmas to the antipodes.
Hope it is not too hot down there.
We are even having a heatwave here, +60*F for X-mas !
Hopefully "climate change" brings us some ice age soon !
The sourdough sight is nice, my favorite bread too,
ever since I urinated in the Yukon River on the way to Alaska.
It will be interesting to see where 540-grainers at 1350 fps MV fall on the target in relation to the other .458 WIN-V loads.

Rip ...

Well Ron, we've had a few shockers lately (like 108F a month ago and 111F last week - and Melbourne is the coolest mainland state capital) but today was OK. I guess it got to 86, which was just cool enough to enjoy the traditional hot dinner, washed down with Champagne and a rich sparkling red, at least under airconditioning.

Good luck with your .458 calibre experiments. The .45-70 ones certainly have application to my humble collection and I may yet get that Win Mag if I can think of somewhere to store it and an excuse to placate 'er at the coffee shop.

quote:

Originally posted by ALF:
Ah but there is more to this CUP and PSI thing and manuals:

How much of the data we see listed in manuals are derived from actual testing or what is derived from calculation or then a combination ! Given nature of the testing process it would literally take a lifetime to test each and every load !

Given the nature of beast ( and by that I'm referring to the inherent randomness of our ballistics system ) did the authors / ballisticians of every manual out there actually test every load listed ? Methinks not !

So if not what ballistics model was used to calculate their values ? This then important because each system commonly used assumes certain conditions as values and as consequence either over- or under-estimate values dependent on the mathematical model used ?

ALF: that's another way of saying what I was suggesting "how many here have put their trust in the numbers cited by Accurate (Western)"? The point I was making, or trying to without giving infinite details, was that Accurate transposed their CUP to PSI using math, not by retesting everything. That was to serve as an example ONLY of what often goes-round in ballistic labs! As you say, they couldn't begin to re-test every load. Basically, several powder and bullet facilities simply republish what they did ten years ago in a new manual, and may add some loads for "new" cartridges, bullets and powders.

Please let me cite one example only: Hornady is still publishing the exact same loads in their latest manual- 9th edition as in their 7th edition, though the 500gr RN Interbond has changed to a 500gr DGX!

Moreover a good friend and member here, tried to use their 78.3 grain load of AA2230 and locked the bolt of his M70 Winchester. Accurate, of course, has "limited" their max load for the 500 Hornady RN to 72 grains at a very "safe" CUP or PSI. I've used 77 grains in my current Ruger #1 with the 500 Hornady RN, and that was ABSOLUTE max! But that was, as I called it, "an informed judgement" based on case head expansion.

I realize, as RIP has pointed out a few times, that Accurate (Western) has "improved" that powder, and I now understand that it's made in Florida and is the equivalent of TAC.

So, I stand by what I wrote, though perhaps not as eloquent as yourself. In no way do I disparage the use of Accurate powders; I've owned and used AA2460 since it came on the market here, long before I could obtain 2230.

I've also read and used Denton's work some time ago, and it appeared to me from his graph and numbers that CUP and PSI were pretty much linear once the correlation was established -- at least to 60,000 psi.

I've used 81 grains of H4895 with WLRM primers under the 500gr Speer at just over 2300 fps in my current Ruger without a hint of excess pressure, though no manual publishes that because my COL was 3.56", about the same as a Lott. That was all I could get into the case and seat the bullet .25". That would be impossible, of course, at 3.34" COL.

Just explaining where I'm coming from. And in doing so, I run the risk of

RIP has done magnificent work in my view, and I applaud it.

Bob
www.bigbores.ca

Bob,

Thanks.
I just trimmed 142 pieces of twice-fired W-W brass for the .458 WIN-V.
Rather, I uniformed them to 2.500". None shorter than 2.495".
I forthwith consider .458 WIN-V maximum brass length to be 2.505", trim-to length is 2.500".
The SAAMI .458 Win.Mag. chamber length to end of neck is 2.520", which is where the 45-degree bevel down into leade starts.

Stainless steel pin tumble/wash is next, then priming with WLRM.

And for amusement, I copy this from the Heym/Sako thread:

quote:

Originally posted by RIP:

quote:

Originally posted by gbs:
I tried my Heym 416 Rigby Martini Express and the bolt can easily be closed on a loaded round. I also checked the extractor and it is undercut. I could not see the bolt clearly but I would expect it is cut to match the undercut on the extractor.

Thanks. Makes sense. That's the way I like them.

A few years back a PH was severely mauled by a lion. With the lion on the PH a "modern 416 magnum rifle" fired one shot and then could not be opened to extract. To me this is an advantage of the older large case calibers such as the Rigby. The operating pressure is significantly less and they are therefore less likely to fail to extract.

Also, why a SAAMI .458 WIN with 500-grainers at 2200 fps and 60,000 psi is better than a SAAMI .458 Lott with 500-grainers at 2250 fps and 62,500 psi.

Load that .458 WIN-V at 3.6 COL and you can get same bullet going same speed as in the .458 Lott at lower pressure.
Might get a 480-grainer doing 2300 fps at about 55,000 psi, with the LongCOL .458 WIN-V.
Whatever the absolute numbers, at 3.6" COL, The .458 WIN-V can go faster than the SAAMI .458 Lott and at lower pressure than the .458 Lott.

Thus I have confidence in my Winchester M70 Classic .458 WIN-V-3.6", and my Winchester M70 FN/SC SAAMI .458 WIN-3.34".

If you must use a .458 Lott, better make it a Mauser M98 Magnum with Controlled Round Extracting.
No Brevex please but a Heym would do nicely.

Rip ...

Rip ...

After a third firing of my .458 WIN brass I will anneal.
I would expect annealed brass will be easier to trim than work-hardened brass.
It would be nice to get three firings and anneal before trimming.

Lessee ... anneal before necking up and after necking down seems to be a Ross Seyfried suggesting for wildcat brass forming,
when necking up or necking down.
So, after three firings of .458 WIN brass:
FL size, neck anneal, and then trim, in that order,
hopefully, next time.

I am thinking of annealing brass like I read in an article in THE DOUBLE GUN & Single Shot JOURNAL:

Dip case neck in 3-in-one oil.
Hold neck in molten lead for 12 seconds (for a .475 NE No.2 3.5").
Quench cases in water.

Time in lead is the question.
12 seconds was for a much bigger case than the .458 WIN.
I would use 700*F lead.
I would use a bare hand and drop case in water before it got too hot to hold.

Then tumble/wash the cases again.

Sumbuddy who know about molten lead annealing of brass?

Rip ...

Using the Western Powders Co. method of converting CUP to PSI, now that I realize how good that is below 60,000 PSI,
makes the HODGDON ANNUAL MANUAL more pressure-knowable for me.

Comparing the Hodgdon data from 2002 to that of latest edition (2020),
it is obvious that Hodgdon refuses to abandon the CUP system for the .458 WIN.
They have been adding new bullets since 2002, and now own the IMR powders, data for all reported in CUP.
They show one load in the 2020 edition with maximum pressure of 53,000 CUP, for the .457"/510-gr WIN SP.
As Bob pointed out, the pressure for that load (IMR-4895) converts to 62,540 PSI and has a COL of 3.340".
I bet Hodgdon is just reporting old, inherited Dupont/IMR data on some of the IMR powders.
Keeping all their newer data with the newer bulltes as CUP.
For consistency ?
I take that with a grain of saltpeter.
Hodgdon is still using CUP pressure-testing equipment?
Or are they converting their new piezo PSI values to CUP ?





Rip ...

The 460 Weatherby Magnum is gone by 2020, or sooner.
The .458 Winchester Magnum data just keeps growing.

Example: 250-grain Barnes TSX FN in the .458 Win.Mag. at 2.950" COL from a 24" barrel, with 76.0 grains (compressed) of H4198:
2952 fps
50,600 CUP or, about 59,700 PSI.
Close enough.

Lengthening the COL allows great pressure reduction benefits, more so than velocity increase,
but it allows both.

Basically, with long enough bullet, the .458 WIN-V-3.6" can equal or exceed a .458 Lott-3.6", and do it at lower pressure.

Rip ...

quote:

Originally posted by ALF:
RIP

I must say I applaud your passion and staying power on this ! You should be a salesman or a politician ( just before an impending election)

But here is the problem ( if you may? ) Where does the next generation of intrepid hunters actually go out to buy a 458 Win ? Or put another way who actually builds 458's commercially ?

Just for kicks I have been scouring the Canadian gun trade online and through Canadian Access to Firearms and cannot for the love of me find a single 458 Win in a bolt gun for sale ! Brass is equally difficult to find.

No Sorry I did find one in a Zastava Mod 70 but as that goes it's not really a DG gun.... will need some custom work to make it into a DG gun which here in Canada is another story.

CZ in Czech Republic dont even offer their top line 550's in 458 Win, you can get it in the Lott but not the win. There is some lower model in 458 win but as rumour goes the whole caboodle will be gone soon.

I see Winchester offering it but actually laying hands on one is another story!

So whilst there is a wealth of mined data from load manuals past and your commendable work the sad reality is that the sun is setting on your 458 Win ! Come to think of it DG hunting as a whole !

+1

Not on the 458win stuff of which I know little beside owning a 458 Lott I want to get rid off.

But the sun is setting on the whole dg African hunting scene. Give it 10-20 years. Most African hunters don’t pass away on safari. Hunting stops earlier. Just seeing the age of crowd at sci should give an indication.

Mike

Rip might see the pain of a fellow traveller in ALF's post: I am death to product - whenever I find something in the shops I really like it is doomed to delection/close out.

As you know, I can no longer find new reticle-movement hunting scopes (despite a renewed shooter concern with mounting all scopes properly) and must be content with buying old ones - but maybe there is another way to keep the 458WM alive.

Have you considered using 458WM Long-COL rounds in the Lott? Forgive me if this possibility has already been dealt with in the previous 170 chapters.

Rip,
When reading your recent data on shooting Marcella, I noticed that she has a 23 inch McGowen barrel.

The McGowen barrel was new to me until I began testing each 24 inch barrel separately on my then new Simson .405 WCF double rifle. After burning some serious powder, I was pleased to find that each barrel consistently shoots into less than one MOA for with 300 and 400 grain Hornady bullets. These accurate barrels formed the basis for gun maker Aaron Little to re regulate the rifle so that it puts the four bullets from two Right and Lefts in to well under one inch at 50 yards. Though not a target rifle, such accuracy does make me more confident when hunting. So far, field performance is 100%.
South Texas Nilgai- another one shot kill.