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

Sir Jerry,
Buy a donkey for that.
I wonder if Mr. Turnbull had to do anything fancy to get a COL of 2.985" to work through a Browning '86 .50-110 WCF ?

I have a .45-70 Browning '86 and have not gotten the "longCOL" dummies for that made up yet, will see how far it will go.
Interesting that with a brass length of 2.145" for Johnson's .450 Alaskan, a COL of 2.985" allows a bullet projection of 0.840".
That is exactly same as for the .458 WM with max BL of 2.500" and COL of 3.340".

For the .45-70 Long Throat of Bob Mitchell, with 2.105" max BL and COL of 2.985", bullet projection is 0.880".
Bob's throat was not quite as long as that of the SAAMI .458 WM, he never specified it that I know of.
Putting the SAAMI .458 WM throat on a .45-70 Government would have to be called a .45-70 LT+ as a specifier.

bcelliott,

Dave Kiff, PT&G, has the reamer for a "450/348 Ack Imp" with a reamer shoulder diameter of 0.5350" (40 degrees)
as compared to his "450 Alaskan" reamer with a shoulder diameter of 0.5210" (16*32').
Those are reamer minimums.
The brass maximum for the traditional 450 Alaskan is 0.5200" (16*30') at the shoulder diameter, so only 0.001" tolerance minimum. That'll double headspace a rimmed cartridge.



The .450 Alaskan pictured at ammoguidedotcom is slightly different, mostly in length of brass (2.250") which gives it a longer neck,
and the neck is tighter and with no taper. The algorithm used there to calculate gross water capacity yields only 88.1 grains, not reality:



Greater taper feeds better, but bolt thrust reduction is a great selling point for the AI version, according to Ackley.

I will scan the improved and traditional reamer drawings and do a simple RCBS cartridge design for the PT&G AI reamer
and get it up here, later, for fun.

More fun is still awaiting wind, weather, and domestic chores getting in the way of shooting those BP loads for the .458 WM+ and .45-2.6" SWT.
I need to go to a private range so as to use the Oehler 35P at 10 yards instead of 5 yards, with a 100-yard paper target.
This is in hopes of the lube wads doing no damage to nor fooling the chrono.
Such a setup is not possible at the public range.
Will have to SWAG a 10-yard correction to MV.

The PT&G 450 Alaskan reamer would chamber for another variation of the cartridge:





The PT&G 450/348 Ackley Improved:





Yep, using the cylindrical .50 brass long enough to make the 2.255" brass length and the 0.502" neck is appealing,
with possible benefit of less bolt thrust and longer case life.

So I get some .45-70 Gov. W-W Super brass all measuring 2.105" max brass length to try with various bullets
in the Browning '86 to see what the maximum COL is that can be shoved through the loading gate
and levered from the magazine into the chamber.
First I slugged the barrel and found a .457" groove diameter.
The throat is just a 12-ish-degree chamfer from case mouth into the rifling,
basically no throat, on a SAAMI .45-70 Gov:

And of course this inspires the .45-70 Long Throat Plus (45-70 LT+)
which is a re-throating of Bob Mitchell's .45-70 LT with the .458 WM throat.
A one-piece reamer would be nice, to increase the case mouth diameter to same as .458 WM: 0.481"
Rechamber any .45-70, or re-barrel, with any .457", .458" or .459" grooved barrels.





Bob had a .45-70 LT load (that he used in a Ruger No. 1) pressure tested by the Accurate Powders folks,
and was getting very near SAAMI .458 WM ballistics at acceptable pressures,
with a little less throat than on the .45-70 LT+.

But, even the unadulterated .45-70 Govt. will Bagwell with the BHN-10 480-gr PH bullet at 1300 fps.
Saint Bagwell specified a smokeless load with that bullet: 38.5 gr of IMR-3031 for 1350 fps.
Bob Mitchell has touted the 480-gr DGX as a substitute for when the proper FN cast bullet is not available.
The gilding-washed, steel-jacketed 480-gr DGX-Bonded will tolerate being driven faster for sure with 2.780" COL in the .45-70 Govt. lever action or single shot.
For extra flare, adding the longer throat effectively increases case capacity and reduces pressure.

In the bolt-action or single-shot .458 WM and .458 WM+ with 480-grainers of any type, 1300 fps to 2300 fps is plumb tropical.

In one of his rare posts on AR, Turnbull mentioned that one of the problems of the “450 Alaskan” was the large number of variations as it was a wildcat that was never standardised. That means you need to be careful to find loading dies to match what ever chamber you might have. This was one of his reasons for coming out with the 475 Turnbull (which is standardised and listed by SAAMI). As an aside I think he recommends 2.75” as the OAL max for the 475.

Years ago I wanted something with a bit more power than a 45/70 and after considering the options I had a 45/90 built on a Browning 71. In hindsight I had a Browning 1886 and all I had to do was either alter the throat or use bullets that were bore riders. You can effectively achieve 45/90 ballistics from a 45/70 in an 1886 by doing that. Below is a link to another site where I had another poster put up some pics of various 45/70 loads with different bore riding designs, some of which were loaded to 45/90 length. The ones pictured can be loaded into the mag, chambered and ejected unfired from a stock Browning 1886.

https://levergunscommunity.org/viewtopic.php?t=71103

One of the reasons users like the 45/70 is they enjoy good accuracy and performance using cast pills. As shown above it’s not that difficult to gain improved ballistics using the stock throat and simply selecting the bullets used. Doing this also means you can use regular 45/70 brass and loads, providing huge load flexibility. It’s similar to your SAAMI length and long col loadings for the 458WM.

I find the 458 WM throat great for dissipating pressure but far from ideal for cast bullet use. I know you’ve cracked the code, which is a huge achievement but if I was going to improve on the 45/70’s no throat design I’d add a throat similar to the 450 Marlin.

Apart from several Marlins and NEFs in .45-70, I've owned a total of two .45-70s in the Ruger No.1, and the second one, that was NIB, had a shorter throat than the first that I bought second hand. So I had the throat lengthened on the second due to its shorter throat and because I wanted to seat the long monolithic bullets in particular out of the case farther giving more room for powder. Being a single-shot allowed this of course.

So all bullets for the Ruger No.1 .45-70 LT (long throat) were seated to the same depth whether a 350gr TSX or a 500gr Hornady, that being 1/4"; the 500gr taking no more space in the case than the 350, or even an ordinary 300gr Hornady. Of course, the shorter bullets also had a shorter COL. My "smith" lengthened the throat by 0.30" which was about perfect for what I wanted. That allowed a COL of 3.19" for the 500gr Hornady and the 450gr Swift. But those two were only about 25/1000" off the lands, keeping the psi high enough for the results obtained: 2200 fps for the 500 and 2300 fps for the 450. I was also getting 2530 fps for the 350 TSX and up to 2700 fps for the 300 TSX but I settled for 2650 for better accuracy from the 300, and 2470 fps from the 350 TSX for the same reason.

I gave the first No.1 to my second son and was getting +2000 fps from the 500gr Hornady at 2.93" COL. The powder was AA2015BR, and was tested for me at the Accurate facility and pronounced "safe" in the Ruger from its 22" barrel. They got about 2100 from their 24" test barrel. The longer throat in the new Ruger No.1, plus a slower powder (H335) added about 200 fps to the 500.

The last Ruger was my favorite rifle for two decades for any and all big game hunting. However, at 8.4 lbs with scope, sling and 4 in a buttstock cartridge holder, recoil was arouund 50 ft-lbs average, and over 70 for the 450 Swift or 500 Hornady. It will soon be 3 years ago that I traded it for the No.1 in .458, not because I wanted any increase in ballistics, but approximately the same with about a 30% reduction in recoil due to the extra two pounds and Mag-na-ports of the .458. The 24 inch barrel and larger case of the .458 does add up to 150 fps for certain loads over the LT, but now I'm focusing on reduced loads due to age and arthritis.

To illustrate how throat length can affect results from the Ruger No.1 in .45-70 (or the .458 and other cartridges) we need only compare two SPEER manuals for their 400gr in .458. In #11 the results using 62 grains of RL-7 at COL 2.76" in the #1 Ruger .45-70 test rifle resulted in a max of 2178 fps at less than 35,000 CUP. In their #12 manual the COL was shortened to 2.54" due to new info that Ruger had shortened the throat of that rifle. That limited a max load of RL-7 to 52 grains at 31,000 CUP and 1934 fps. The difference was 4213 ft-lbs from a COL of 2.76" vs 3322 fp-lbs from a COL of 2.54", a difference of nearly 900 ft-lbs!

But by limiting the Ruger to a max of 35,000 CUP in either case, they've vastly misrepresented it's true potential. I was told by a Ruger rep that the Ruger No.1 in .45-70 and in .458 have the same strength!

Bob
www.bigbores.ca

JFE, thanks for the reply, plenty for study there:



Buy a donkey for those flowers about "cracking the code" on cast bullets in the SAAMI .458 Winchester Magnum.
Very simple:
Hard-cast lead alloy with powder-coat paint and sized to 0.002" greater than groove diameter with smokeless powder.
Gas check is optional for sub-1800 fps loads, add a gas check for plus-1800 fps.
If you stay below 1400 fps, softer bullets matching the groove diameter perform adequately with PC paint or grease-lubed.
The jury is still deliberating on paper-patched BP loads, surely a verdict coming this week.

SAAMI chambered throat minimums:

.45-70 Govt. (brass length 2.105" maximum):
chamber mouth diameter 0.4827" at 2.1099" chamber length >>> chamber mouth chamfer at 12*45' >>> ends at bore diameter of 0.450" at 2.1789" length from breech bolt face to start of fully formed rifling.

.450 Marlin (brass length 2.100" maximum)
chamber mouth diameter 0.4827" at 2.1179" chamber length >>> chamber mouth chamfer at 12*45' >>> ends at diameter of 0.465" at 2.1570" length >>> 2*30' leade starts at 0.465" diameter 2.1570" length >>> ends at bore diameter of 0.450" at 2.3288" from breech bolt face to start of fully formed rifling.

.458 Winchester Magnum (brass length 2.500" maximum)
chamber mouth diameter 0.4830" at 2.5200" chamber length >>> chamber mouth chamfer at 45* 0' >>> ends at diameter of 0.469" at 2.5270" length >>> 0*29' 30" leade starts at 0.469" diameter 2.5270" length >>> ends at bore diameter of 0.450" at 3.6420" from breech bolt face to start of fully formed rifling.

Assume .458" bullet diameter and groove diameter for all three of the above chambers.
.458-caliber cylinder travel from maximum brass length to start of .458"-grooved rifling in throat,
which I like to call simply the "slug jump" of the throat:

.45-70 Govt. = 0.0611"

.450 Marlin = 0.1372"

.458 Winchester Magnum = 0.6725"

The .450 Marlin throat is hardly any different from the .45-70 Govt. when it comes to being able to use full diameter bullets for breaking the code.

Sir Bob,

That settles it for me. I am forgetting the .450 Alaskan of many different chambers.
There can be only one .45-70 LT+.
Just re-inventing your wheel.

Harold "Bill" Fuller (on the right) was the machinist-gunsmith for the 450 Alaskan(s) and 50 Alaskan of Harold Johnson.
Along with his own .450 Fuller, he built Hawken-patterned muzzleloaders too:



Johnson's Mom & Pop country store and firearms factory from the 1950's:



I passed by that location many times in the late 1980's and early 1990's, ignorant of its former glory.
I shall return to that place on a nostalgic tour to see what is left.
But good bye to the idea of converting Browning Winchester 1886 or M71 to .450 Alaskan,
when there is the magic of the .458 Win. Mag. throat to be applied in the .45-70 LT+.
Even a stock 1886 .45-70 Govt. can handle the 480-gr Hornady DGX Bonded at 2.780" COL
fast enough to make bloody big holes through anything needing it.

The forearm tip banding that Fuller and Johnson used to keep the tubular magazine attached to the rifle
might be a good idea on a .45-70 LT+ ...

Good historical stuff !!!
Sooo many things have been done to upgrade Winchester lever guns that I feel a bit guilty just loading my 1886.45-90 ( .458 2.4 ) and shooting it.

But the 450 grain Kodiak and 450 grain Punch bullets at 2150 fps did the job on ele. Cape Buff. water buff, etc so well, there was no reason to tinker with the actual cartridge or modify the rifle.

Another stop on the nostalgia tour, where in 1938, the .458 Winchester Magnum was conceived by way of the .450 Watts Magnum/Short:

Bob - that was an interesting read about your experiences with the 45/70 Ruger No.1. Launching 500gr pills at 2000 FPS from a 7lb rifle would have been too much for me.

For the sake of clarity, your second Ruger No.1 that originally had a no throat chamber, when the throat was lengthened to 0.30” was it given a conventional parallel width throat, ie around 0.459/0.460”?

Good stuff Sir Ron, our buddy here at the 'fire mstevenson sent me that cannelure tool in the pic, i'll use it to roll a nice cannelure on some 500gr Partitions for a COL of 3.585 inch, would be fun to drive those bruisers at 2350 fps from the Great 458 Win Mag+!

Sir Jerry,

That would be a nice mate for your 500-gr TBSS, absolutely.
Here is your new-old canneluring tool, who made it ?





This one from CH4D works nicely for me:











Those are some .510/ .338 Lapua 2.7" cases (".500 Bateleur") made from Captech basic cylindrical (used in an FN Mauser with Wiebe 500 Jeffery bottom metal)
and some 400 Whelen-B+ brass (meant for a 3.6" magazine, M70 Win 6-shooter, with Duane Wiebe XRM box)
both of which can use a homemade cannelure on some bullets.

Back to the .458 WM+ and .45-70 LT+, the Barnes Buster 400-grainer has been advertised with two cannelures,
but I have to put the second cannelure on the ones I have found.
It will be great in a .45-70 LT+ for "deep penetrating bone crushing" backup of a milder mannered 405-grainer.





And the best use for .458 Lott brass, make quick work of them:



And another funny swiped from the image gallery here, thanks to member shaman:

Thanks Sir Ron, not a mark on that thing, either someone couldn't buy/find what they needed and just made one, fine job rolling on those cannelures, are those old Barnes or Hawk bullets with the pin hole in the bases?

LOL on the gcu target! ; ]

Yes it was. And the pressure was evidently less though MV was increased by 200 fps from the 500 Hornady. That was due not only because of the relatively long throat but mostly being able to use a relatively slower ball powder (H335) compared to the faster stick powder (AA2015BR). The increase in the powder charge was 15 grains. That would not have been possible in the use of H4895, for example, because of its coarse grain stick powder. It was H335 that taught me to later use it in the CZ550 in .458 Win. I used a magnum primer to ignite H335 being a ball propellant - that being WLRM.

Bob
www.bigbores.ca

Bob - thanks for clarifying that point. I get the value in throating using a parallel throat.

What I don’t understand is why in the 458 Win Mag the throat starts at 0.469”?

Was it to dissipate gases faster? Your trials with the Ruger No.1 indicate that a similar performance increase may be possible without the need to use such a radical throat design.

Sir Jerry,

Those were Barnes Original .510-cal./ 600-grainers with the hole in the base, and having varying amounts of lead smear showing,
squeezed out of the "pinhole." The Barnes Buster .458-cal./ 400-grainer has a pinhole at both ends, but they are much tidier.
I wonder if that would allow the Buster to be a legal "soft" where solids are not allowed for hunting ?

Now I must render an accounting for your charitable donation of bullets to the Crusade. First the .458-sized/ 570-grainers
used in .458 WM+ with duplexed BP:











"Lube star" at the muzzle, and if there was any lead fouling it was minimal, easily cleaned up: