The Accurate Reloading Forums
458 winchester magnum
03 September 2019, 13:44
RIP458 winchester magnum
Bob,
Thanks for that input.
Sounds like you have as little problem with the long box as I do.
And thanks for goading me into trying the 480-grain DGX.
More to come on that.

Rip ...
03 September 2019, 13:46
RIPquote:
Originally posted by Fury01:
Rip, Some actual COL's for The Mission.
3.275 on the Glenhill 435's cast and 3.265 on the Gardner 485's
Accurate Powders lists 55 grains of AA2105 as a max load with a 475 grain LY457406 bullet at 1886 fps.
Recorded for posterity, and THE MISSION, thanks, Dennis.

Rip ...
03 September 2019, 13:50
RIPSome follower lengths versus magazine box inside lengths,
may be of interest in considering 3.8", 3.6" and 3.4" box lengths for the .458 WIN:
CZ 550 Magnum: 3.540" follower in 3.840" box (from measurement of one factory .458 Win.Mag. rifle)
Dakota M76 African: 3.540" follower in a 3.860" box (from measurement of one .416 Rigby action bought for custom job)
(other Dakota and CZ follower pics and measurements to follow.)
MRC box blocked at back like an M70 Classic, follower is aluminum:
Pre-'64 M70 H&H-length with no block at back of box, steel follower:
03 September 2019, 14:05
RIPBelieve it or not, this is a CZ 550 Magnum .505 Gibbs magazine box, a ribbed .375 H&H box with the front wall cut down,
and a sheetmetal extension welded in place.
This is how CZ-USA did their first batch of .505 Gibbs "Safari Classic" rifles, way back when.
More to come, on followers and boxes.

Rip ...
03 September 2019, 17:23
JFEThanks RIP and Bob for all the additional info.
I called Winchester Australia today (they're the local agents for CZ) to enquire about mag boxes and followers.
The part number for LH 375 followers and RH 375 & 458 followers are the same, so no difference there.
Of course no local stock of 458 mag boxes but I can order one. The downside is it may take 6 months to get here. I'm on the hunt for one if anyone can help.
03 September 2019, 23:55
Head TraumaRIP thanks for the measurement
Looking at a lightly used current production M70
Safari 458 and thinking about replacing the factory front sight with an NEC banded front sight, hence the inquiry. NEC has one with a 0.748 ID that will work.
The factory front sight measures 0.585" from the
top of the barrel to the centerline of the sight
bead. The NEC banded sight measures 0.385" to the bottom of the sight blade dovetail.
Needs a 0.200" sight insert to equal the factory.
They have a 3/32" bead at 0.237", measured to the
top of the bead, we may have a winner.
Thanks all.
04 September 2019, 05:37
Fury01Rip,
A couple of years ago, I replaced my Factory Whitworth follower and spring with as new M98 military units. I left it un-beveled so the bolt won't close on an empty magazine unless depressed by hand. I found the M98 units a bit stronger on the uplift and feeding is just fine. For The Mission.
"The liberty enjoyed by the people of these states of worshiping Almighty God agreeably to their conscience, is not only among the choicest of their blessings, but also of their rights."
~George Washington - 1789
04 September 2019, 12:27
RIPFrom thread entitled "Current M70 458WM Safari factory muzzle diameter"
quote:
Originally posted by Head Trauma:
Last one I measured was 0.728" but that was a while ago.
Thanks
Reply to Head Trauma copied from other thread,
for THE MISSION:
About same as what I got on a year-2011 M70 Super Grade Safari Rifle .458 Win.Mag.,
24" barrel with 0.730" muzzle diameter.
Not latest production.
I bet they don't sell many lately.
Sad.
Thanks to sambarman338,
quote:
Originally posted by sambarman338:
For the sake of the mission, Head Trauma, may I suggest future discussion of this matter be conducted in the 458 Winchester Magnum thread?
Head Trauma replied here, good work Paul!
quote:
Originally posted by Head Trauma:
RIP thanks for the measurement
Looking at a lightly used current production M70
Safari 458 and thinking about replacing the factory front sight with an NEC banded front sight, hence the inquiry. NEC has one with a 0.748 ID that will work.
The factory front sight measures 0.585" from the
top of the barrel to the centerline of the sight
bead. The NEC banded sight measures 0.385" to the bottom of the sight blade dovetail.
Needs a 0.200" sight insert to equal the factory.
They have a 3/32" bead at 0.237", measured to the
top of the bead, we may have a winner.
Thanks all.
Sounds like a great plan.
The original .458 WIN African had a 3/32" silver bead.

04 September 2019, 12:49
RIPJFE,
The .458 WIN and .375 H&H CZ 550 Magnums do seem to have same follower.
But there is a different follower that CZ-USA put into my earliest production .404 Jeffery from Kansas City, Kansas.
I think it is the same one they use in the .416 Rigby,
but they used it in a ribbed .375 H&H box for my 404 Jeffery "Safari Classic" rifle,
and it was the slickest feeder I ever had right out of the box from CZ,
and held 5 down in the box, 404 Jeffery.
What appears to be the standard .375 H&H follower used in the non-ribbed ".458 W.M." box is what works best in Bobbarrella.
Feeds well, after some gunsmith polishing of rails and ramp.
And her bolt will close over 6 cartridges in the box, .458 WIN.
I photographed and measured two loose Dakota M76 African followers, and two followers from CZ 550 Magnums.

Rip ...
04 September 2019, 12:53
RIP
Scale at right is inches, graduated in 1/10th inch.
04 September 2019, 12:53
RIP
For what it is worth, rough measurements, and there are numerous other differences amongst all four followers.
see more pictures below.
I think DA1 is for .416 Rigby, DA2 is for .375 H&H, for Dakota Arms M76 Africans.
CZ1 is from the "Safari Classic" 404 Jeffery, used in .416 Rigby also.
CZ2 is from Bobbarrella the .458 WIN, used in .375 H&H also.
04 September 2019, 13:04
RIP
04 September 2019, 13:05
RIP
04 September 2019, 13:06
RIP
Horizontal scale at bottom of pic is graduated in cm and mm.
04 September 2019, 13:27
RIPCZ3: A third CZ follower I measured was from the .505 Gibbs. It looked exactly like the .375 H&H/.458W.M. follower CZ2 above.
Front and rear widths were same: 0.715" and 0.940" respectively.
However, the length was 0.010" SHORTER (3.530")
and the thickness/height in the middle of the follower was 0.015" THINNER/LESSER (0.260")!
DA3: A third Dakota M76 African follower was measured, the one that came in my .416 Rigby "parts" action, ordered from Brownells back when you could get them there.
It is most like DA2 above, what I thought was for the .375 H&H.
DA3: 0.785" front width, 0.920" rear width, 3.540" length, 0.300" thickness/height amidships.
CZ 550 Magnum ".458W.M." magazine box inside length: 3.840".
Dakota M76 African ".416 Rigby" magazine box inside length: 3.860".
04 September 2019, 13:33
RIPNow back to the funny business of a first edition CZ Safari Classic .505 Gibbs magazine box:
04 September 2019, 13:36
RIP
04 September 2019, 13:37
RIPView of top front end of box, outside front:
04 September 2019, 13:39
RIPView of top front of box, inside box:
04 September 2019, 13:41
RIPView of bottom front of box, outside of box:
04 September 2019, 13:42
RIPView of bottom front of box, inside of box:
04 September 2019, 13:45
RIPMagazine box viewed from bottom of magazine well, in stock, against action bottom,
holds 3 of the .505 Gibbs cartridges:
04 September 2019, 13:48
RIP
NO NO NO! Do not trim off the feed ramp overhang.
Instead insert a 0.100"-thick steel plate inside front of box,
and bevel top edge smooth to blend into feed ramp.
This will also reinforce front of box from the inside, against battering from bullets in recoil.
It will also reduce inside length of magazine box to 3.850" instead of 3.950".
The rifle came from CZ with a rectangular rubber pad located where the red arrow above is pointing.
That would be an example of how not to extend your magazine box.
I think CZ-USA learned to do better.
This might be helpful guidance when extending a standard M98 Mauser magazine box from 3.4" to 3.6" length,
for a .458 WIN to beat any SAAMI .458 Lott.
This has been presented, for THE MISSION.

Rip ...
04 September 2019, 14:03
RIPquote:
Originally posted by Fury01:
Rip,
A couple of years ago, I replaced my Factory Whitworth follower and spring with as new M98 military units. I left it un-beveled so the bolt won't close on an empty magazine unless depressed by hand. I found the M98 units a bit stronger on the uplift and feeding is just fine. For The Mission.
Milsurp or Brownells!
Rip ...
04 September 2019, 17:53
Fury01Milsurp. I had bought a few sets back in the day. Sarco, Gunparts or someone long forgotten. The hefty spring is what drew my attention. I tried the follower on a whim. Works so well I just left it in.
"The liberty enjoyed by the people of these states of worshiping Almighty God agreeably to their conscience, is not only among the choicest of their blessings, but also of their rights."
~George Washington - 1789
05 September 2019, 11:20
RIPI once tried to straighten out the hump in a Winchester M70 magazine spring, with a hammer and anvil.
The spring broke clean as glass.

Luckily, I have never seen a Mauser spring with a hump in it.
Speaking of bottom metal,
Duane Wiebe's XRM mag box for the M70 has an inside length of 3.645".
The follower he made to fit that XRM box has a length of 3.325".
Seems that a follower that is about 0.300" shorter than the box is a desirable thing,
for a .458 WIN mag box, whether 3.4", 3.6", or 3.8".
I need a spring for that XRM box, a good, stiff, well tempered Mauser spring would be good.
Swapping springs and followers can be rewarding.
Also, getting the sharp edges and corners of the follower, box, rails and feed ramp
smoothed and polished
is a very good thing.

Rip ...
05 September 2019, 18:10
Fury01Rip
Let me know if you need a spring. I’ll dig around over the weekend and see if I have another 98 spring.
"The liberty enjoyed by the people of these states of worshiping Almighty God agreeably to their conscience, is not only among the choicest of their blessings, but also of their rights."
~George Washington - 1789
06 September 2019, 14:39
RIPFury01,
Thanks, but I have been scavenging Mauser springs, enough for my needs so far.
All this stuff about Woodleigh Weldcores coming apart in game (batch of faulty bonding?) got me to looking at their offerings.
That .458/480-grain Hydro-Brass-Solid has some nice crimping locations for the .458 WIN with "Any COL You Want."
That might be excellent backup for "Tropical" loads with 480-gr DGX and 480-grain hardcast.
Also the .458/500-grain Trophy Bonded Sledgehammer
"solid"
and the Bear Claw "soft"
now have some admirable crimping locations to allow one to beat a SAAMI .458 Lott.
That aspect, at least, of the TBSH and TBBC is improved.

Rip ...
06 September 2019, 17:35
sambarman338The Woodleigh Hydros might work well with the long throat and the CZ magazine. I've had trouble with them in lesser calibres where either the throat or the action length meant they took up too much powder space.
07 September 2019, 00:39
JFEquote:
Originally posted by RIP:
JFE,
The .458 WIN and .375 H&H CZ 550 Magnums do seem to have same follower.
But there is a different follower that CZ-USA put into my earliest production .404 Jeffery from Kansas City, Kansas.
I think it is the same one they use in the .416 Rigby,
but they used it in a ribbed .375 H&H box for my 404 Jeffery "Safari Classic" rifle,
and it was the slickest feeder I ever had right out of the box from CZ,
and held 5 down in the box, 404 Jeffery.
What appears to be the standard .375 H&H follower used in the non-ribbed ".458 W.M." box is what works best in Bobbarrella.
Feeds well, after some gunsmith polishing of rails and ramp.
And her bolt will close over 6 cartridges in the box, .458 WIN.
I photographed and measured two loose Dakota M76 African followers, and two followers from CZ 550 Magnums.

Rip ...
Thanks RIP. You need to use all the info, references, test data, articles and anecdotes you have gathered on this thread and publish a book on the 458. It would make a great reference work for 458 fans.
A friend of mine has had a 404 built on a 375 CZ550. The 375 follower was reprofiled to feed the wider bodied case and still uses the ribbed 375 mag box. That rifle feeds perfectly. The ribbed box doesn’t seem to affect the feeding of bottleneck cases. With my conversion I should also add that some 458 cartridges fed OK through the ribbed box, just not all of them.
I managed to locate the 458 mag box I require. The rifle also needs some stock surgery as the stocks on those rifles are large in practically every dimension. I find the stock quite clumsy to use in its current state.
I had a pop up aperture sight from an early 602 fitted to mine and I really like it. It has plenty of sight adjustment and I like the way it folds out of the way when not in use. It’s a really handy idea. I will order a couple of replacement front sights as my aging eyes are having difficulty picking up the factory fitted fine bead. For those interested alternatives are available from NECG.
07 September 2019, 01:03
JFEThe designer of the Hydrostatics mentioned that it was the shape of the bullet that gave the bullets the ability to drive deep and in a straight line. He also experimented with lighter weight bullets - at the time he was trying 235gr pills in a 378 Wby and was driving them quite fast (for a solid). He suggested that as the speed increases the wound channel approaches the wound channel created by an expanding soft nose bullet but with far superior penetration. I’ve heard the same from others who’ve used them in this way.
In 458 caliber Woodleigh make Hydrostatics in several weights/length projectiles: 325, 400, 450 and 480 gr. So there is plenty of opportunity to experiment.
The other point is that Woodleigh make a plastic tip to provide better feeding characteristics. The plastic tip is designed to with stand the recoil forces of being moved around in a mag box but shatter on impact when it reaches the target.
07 September 2019, 09:24
sambarman338quote:
Originally posted by JFE:
... I will order a couple of replacement front sights as my aging eyes are having difficulty picking up the factory fitted fine bead. For those interested alternatives are available from NECG.
What sort of front sights are you thinking of, JFE? I know beads are
de rigueur for express sights but peeps allow you a bit more choice.
You might recall my telling of the buffalo I was directed to shoot, so distant the 1/10th-inch bead covered three-quarters of it; though my rifle shoots high even when taking the finest bead, the nature of beads suggests the impact should be within the centre of the circle, so my shot still went a little high.
With fat, square posts you can centre the target above the flat top, without lateral sun glint distorting your concept of centre. I'm not against the sight catching light, though, so file my posts off at 45 degrees if I can't find a store-bought sourdough. If you keep that angle shiny, it works nearly as well.
I guess NECG's patridge sights would be nearly as good.
07 September 2019, 10:59
RIP6 hours ago, I fired the latest .458 Winchester Magnum Flanged (.458 WMF) aka the .45-100 2.6" Sharps Winchester Throated (.45-100 SWT),
in a 28"-barreled (1:18" twist) Ruger No.1.
These test loads were fired in the new chamber:
GUNSMITH fired the first one at his shop's test berm, at Falls of Rough, Kentucky.
Then I met him at his 100-yard range,
as he had other work to do on the farm pond (deer watering hole) and rifle range,
and I needed to take a fatter forearm to him to better fit the fat octagon barrel.
The rifle had no forearm and no sights yet,
but the 20-MOA Leupold Mark 4 Picatinny had been installed.
I pointed it at the 100-yard gong, a huge 24" steel disk.
I fired it twice and each time, nothing was seen of impact.
GUNSMITH said I was probably shooting high, into the tress behind, because of the 20 MOA tilt to the rail that I was sighting down.

So I tilted the muzzle up a little, so I could see that empty dovetail for the front sight, then lowered it until it was just hidden by the end of that Picatinny, pointed at the gong.
My third shot was only 2 or 3 inches from the center of the gong.
The PC-painted Linotype slug made a big splash on the freshly white-painted gong that could be seen by the naked eye at 100 yards.
And the gong made a music-to-my-ears note.
This rifle shoots pretty close to where you point it, even with no sights.
Hot blue, install forearm and front sight, and it will be ready.
Recommended plinker load for any .458 WIN, Belted or Flanged:
Lyman #457125, plain base "Government" RN, cast in Linotype and PC-painted with Harbor freight red, and sized to 0.461": 487-grains
.45-100 2.6" SWT COL = 3.350" (Starline brass)
.458 WIN (Belted) 2.5" COL = 3.250" (SAAMI satisfying) (Hornady brass)
F-215 primer
40.0 grains AA-5744 (NO FILLER)
This is a Lyman Manual load for the .45-100-2.6" (45-100 Sharps).
In a 29.5" barrel of 1:20" twist with bullet from same mould but cast in Lyman #2 (500 grains),
MV = 1646 fps
Pressure = 27,000 CUP, which for this cartridge is probably very close to 27,000 PSI.

Rip ...
07 September 2019, 11:07
RIPquote:
Originally posted by sambarman338:
The Woodleigh Hydros might work well with the long throat and the CZ magazine. I've had trouble with them in lesser calibres where either the throat or the action length meant they took up too much powder space.
Paul,
Using your method of ruler and calculator on image of bullet, and Woodleigh report that the .458/480-gr HSS brass solid is 1.466" long,
I figure that crimping on the middle of 5 cannelures will give a COL with 2.5" brass of 3.567".
That will be enough to beat a SAAMI .458 Lott.
I have also ordered a Woodleigh reloading manual.

Rip ...
07 September 2019, 11:23
RIPquote:
Originally posted by JFE:
Thanks RIP.
Welcome, and thank you, I am learning new stuff myself here. You need to use all the info, references, test data, articles and anecdotes you have gathered on this thread and publish a book on the 458. It would make a great reference work for 458 fans.
Working on a title.
A friend of mine has had a 404 built on a 375 CZ550. The 375 follower was reprofiled to feed the wider bodied case and still uses the ribbed 375 mag box. That rifle feeds perfectly. The ribbed box doesn’t seem to affect the feeding of bottleneck cases. With my conversion I should also add that some 458 cartridges fed OK through the ribbed box, just not all of them.
And with the Flat-Nosed ones, shorter COL in a longer box may work better ... I managed to locate the 458 mag box I require. The rifle also needs some stock surgery as the stocks on those rifles are large in practically every dimension. I find the stock quite clumsy to use in its current state.
You must have got one with the "Phat American" style of stock.
If so, it could definitely use some bariatric surgery. I had a pop up aperture sight from an early 602 fitted to mine and I really like it. It has plenty of sight adjustment and I like the way it folds out of the way when not in use. It’s a really handy idea. I will order a couple of replacement front sights as my aging eyes are having difficulty picking up the factory fitted fine bead. For those interested alternatives are available from NECG.
Yep, that pop-up peep is great.
Wish I had even one of them.
CZ-USA was offering it as a custom option for an extra 3 or 4 hundred bucks on a new rifle, last time I checked,
maybe even retrofitting to used rifles, but what price for that I do not know.

Rip ...
07 September 2019, 11:34
RIPquote:
Originally posted by JFE:
The designer of the Hydrostatics mentioned that it was the shape of the bullet that gave the bullets the ability to drive deep and in a straight line. He also experimented with lighter weight bullets - at the time he was trying 235gr pills in a 378 Wby and was driving them quite fast (for a solid). He suggested that as the speed increases the wound channel approaches the wound channel created by an expanding soft nose bullet but with far superior penetration. I’ve heard the same from others who’ve used them in this way.
The shorter solids would be more stable, but then you get into the SD/momentum/trajectory issues if you go too light.
In 458 caliber Woodleigh make Hydrostatics in several weights/length projectiles: 325, 400, 450 and 480 gr. So there is plenty of opportunity to experiment.
I noticed the greater weight range of the .458-caliber HSS brass solids. Just another of so many reasons why the .458 WIN is superior,
to all other hunting cartridges.
Combining the .458/400-gr WWC-PP with the 400-gr HSS brass solid is interesting. That might be a real humdinger combo.
The other point is that Woodleigh make a plastic tip to provide better feeding characteristics. The plastic tip is designed to with stand the recoil forces of being moved around in a mag box but shatter on impact when it reaches the target.
Yes, an aid to rifles with feeding issues, but that hemispherical plastic tip will be looked at with a jaundiced eye,
as something else to go wrong if it falls off inside the magazine box and causes a jam.
Better to get a rifle that feeds than to depend on plastic tips.
It ain't like they improve the BC much, or do they make it worse?
And they will lengthen the COL!
Rip ...
07 September 2019, 11:59
RIPquote:
Originally posted by sambarman338:
With fat, square posts you can centre the target above the flat top, without lateral sun glint distorting your concept of centre. I'm not against the sight catching light, though, so file my posts off at 45 degrees if I can't find a store-bought sourdough. If you keep that angle shiny, it works nearly as well.
I guess NECG's patridge sights would be nearly as good.
Ditto.
If I am really depending on an iron sight for function instead of as a fashion accessory,
I prefer a flattop/patridge/sourdough,
and a square-notch rear, or a peep.
Next best thing to the integral peep on a CZ:
https://www.newenglandcustomgu...etail.php?prod=5933S 
Rip ...
07 September 2019, 17:41
Fury01quote:
Working on a title.
Title: Hammering Home the Truth
Subtitle: The Glory of the 458 Win Mag
As told by Ron Berry
For The Mission
All over a picture of a glorious African Sunset and a superimposed long COL 458WM
Your welcome. A mention in the forward will be fine.
Fury01
"The liberty enjoyed by the people of these states of worshiping Almighty God agreeably to their conscience, is not only among the choicest of their blessings, but also of their rights."
~George Washington - 1789
07 September 2019, 18:08
.458 Onlyquote:
Originally posted by Fury01:
quote:
Working on a title.
Title: Hammering Home the Truth
Subtitle: The Glory of the 458 Win Mag
As told by Ron Berry
For The Mission
All over a picture of a glorious African Sunset and a superimposed long COL 458WM
Your welcome. A mention in the forward will be fine.
Fury01

on RIP doing a book on the incomparable .458 Winchester Magnum.
Bob
www.bigbores.ca
"Let every created thing give praise to the LORD, for he issued his command, and they came into being" - King David, Psalm 148 (NLT)
07 September 2019, 21:39
RIPquote:
Originally posted by Fury01:
Title: Hammering Home the Truth
Subtitle: The Glory of the 458 Win Mag
Dennis,
I shall take that under advisement and you shall surely get an acknowledgement
for your contributions to THE MISSION, thanks.
BTW, the Ruger No.1 ".458 Winchester The Flanged," Poison Slinger is nearing completion.
An NECG or AR-15 type peep on the Picatinny (whatever works)
and a tall globe front sight with multiple inserts
will be the backup iron sights.
Any Scope I Want on the Picatinny is primary, of course.
And a tall bipod on the forearm for making a stand in a sitting shooting position.
The Soule sight on the heel of the stock for Farquharson's supine position will come later.
If I had not run off to Falls of Rough yesterday without my cell phone,
I would have posted pics of the rifle in progress,
and that splash of point-and-shoot Linotype near the center of the 100-yard gong,
for THE MISSION.

Rip ...