Home Forums Hunting & Shooting Express Rifles and Big Bores Only .450 Dakota/Rigby 97 grains H4350 500gn

Hello Riflecrank,
I just chronographed the .450 reduced loads using H4895 as discussed. At the muzzle (with my new Garmin) with a cold, clean barrel with 78 grains of H4895 and 500 grain Woodleigh I obtained: 1929, 1904, 2018, 1964 and 2062 fps to give an average of 1976 fps out of the 25" barrel with Federal Mag 215 primers. This was a very pleasant mild load. I will measure 83 grains H4895 next session and hope that is around 2100 fps, and if so, that will be my practice load.

RH,

Good info on the H4895 loads for the 450 Rigby. Have you considered using standard large rifle primers? I use CCI 200s in my 460 G&A H4895 practice loads with 350 grain bullets, saving the Fed 215s for full power hunting loads in it and the 450 Rigby.

Just a thought based on the current primer price situation.

I haven't thought of using standard large rifle primers, but I have some Remington Magnum primers that I want to use up (not that there's anything wrong with the Remington Magnum primers). I will substitute those in my practice loads and use the Federal Magnum primers for my hunting load which is 105 grains H4350 with the 500 grain RNSN Woodleigh at 2300 fps. It really is a joy shooting the reduced loads.

Yes, really good info on the H4895 for the .450 Dakota.
I will make notes and expect same in my rifle.

I bet a foam wad plug (sliced from a roll of caulk backer) would uniform the velocities of reduced loads with H4895,
even though not necessary.
Accuracy might be better and a few fps higher for same charges than without filler.

I now have a wild hair for building a .450 Dakota with a .458 WinMag throat and a 1:16" twist.
It will be called the .458 WMD.

In outdated experience by me,
Remington primer cups were too hard.
Good idea to use them for practice loads.
I quit using them long ago.

As I mentioned previously, I think the very best .458 caliber cartridge would be based on a 2.5" .404 Jeffery case (with dimension changes) and throated with your favorite .458 Win Mag throat. Built to weigh 10 lbs inclusive of scope on a standard length action...maybe even a Ruger, but have an extended mag to hold 4 rounds, 22" barrel. But I would only do it with properly head stamped brass. Once the recoil gets to around 2300 fps with a 500...that's about my limit for recoil, so the extra capacity of the Rigby sized cases is almost wasted on me. (Don't think I would be good with a .577 and 750's).

That’s a good plan, RH. The MK2 Ruger Hawkeye can easily be modified - mostly modifying the bolt stop - to fit a longer magazine box which fits COAL up to 3.6”.

If you decide to open the magazine box recess laterally - especially on a good aftermarket synthetic or wood stock - it will accommodate a 4th 404 Jeffery case even at 2.8”. That’s the 460 G&A while the 2.5” case would be the short version of same.

MV= 2300 fps is easily achievable with the std 460 G&A version, but as the rifle gets near or below 10 lbs, recoil will demand your attention for fast follow up shots. My preference is to add weight to the buttstock and carry the ‘extra’ 3/4-1 lb over the shoulder than have a lighter DGR and get hammered enough to slow down the 2nd and subsequent shots. YMMV

OK, ya'll have clarified my thinking.

The idea of the .458 Watts Express 2.7" on the H&H case is no more.

I will just stick with the .458/.338 Lapua Magnum 2.7" with SAAMI Winchester Magnum throat tacked onto 2.7" case,
to be used in a 3.6" magazine length,
like a Winchester M70 with drop belly stock and magazine.

I already have that wildcat built on a CZ 550 Magnum.



I need to do it on the Winchester M70 like my .500/.338 LM was done.



The great new development is to call it the ".458 Winchester Magnum Lapua"
abbreviated .458 WML.
Thus honoring the throating of the SAAMI .458 Winchester Magnum, the real performance enhancer.

Ditto the .458 Winchester Magnum Dakota 2.913" on a BRNO ZKK 602.
Maybe I better call that the .450 Dakota Winchester Magnum, for headstamp purposes: .450 DWM
Honoring the .458 WM throat.




These things make the most sense for equivalent nose room in the mag box amongst all three lengths:

2.5" case in a 3.4" box
2.7" case in a 3.6" box
2.9" case in a 3.8" box.

As you see, the 2,8" .458 Lott in a 3.6" box is just all screwed up.

I noticed that B & C now make a Medalist stock (with the aluminum bedding block) for the Ruger which would be my choice as stock after putting one on a Model 70 that split its wood stock. That would mean extending the magazine down rather than laterally to hold 4 rounds because of the aluminum block. I would prefer the chrome moly action (smoothness) cerakoted graphite black rather than the stainless action and put a stainless barrel on cerakoted a dark grey (so scratches don't show as much as with black). I'd have more steel around the barrel to gain weight, to reduce muzzle rise, rather than the butt. I'm running 10 lb 7.4 oz now, so with less ejecta mass with the smaller case, 10 lbs might work for me. Anyway, as the years increase, my desire for lighter rifles increases exponentially, far more than does my adversity to recoil.

RH,

Like you I thought increasing mag capacity meant drop-belly stocks, an idea I find aesthetically unpleasant in most cases. I have a 404J Pre-64 Win M-70 so configured, but Roger Biesen did a great job of making the lines gentle and smooth, so even though it fits 4 cartridges, it doesn’t scream “drop belly!”

However, when I got my Win M-70 Classic 460 G&A back from Gene Simillion, he had built a slightly wider mag box which fit neatly flush in the factory wood stock, retained the one piece bottom metal and, lo and behold, held 4 404 Jeffery cases. I prefer that approach, which can be readily adapted to the Ruger Hawkeye.

I believe Riflecrank, AKA Sir Ron, posted a formula defining the measurements needed to fit specific cases in mag boxes, in the 458 WM+ thread.

Sir Khulu,
Here is the math, turn it 90 degrees and stack the fourth cartridge on the same magazine width:



Hardly ever does a maker follow the law, usually they use a skinnier box width.
Heym may be an exception. Their magazines are cartridge specific.

B&C Medalist is my favorite for M70, M98, Ruger Hawkeye/MKII, and CZ 550 Magnum.

The Ruger Hawkeye/MKII stock weighs about 1 ounce less than 2 pounds.
The M70 LA stock weighs 2.0 pounds.
Here is the B&C Ruger on a .400 Whelen Hawkeye:



And here is same stock on a .300 WinMag destined to be a 20"-barreled .458 WinMag:





That is the "unaesthetic-to-some" Alaska Arms coffin plate sticking proud of the bottom of the stock.

Riflecrank, thanks for that information. I now see that the Ruger would be way too muzzle heavy if I made it 10 lbs with scope with a Medalist stock. Any lighter, will have too much recoil as a .450. Perhaps as a .375 at around 8 3/4 lbs including scope would be better for balance. My Medalist stock on Win Model 70 is 30.5 oz. The "coffin plate" looks good to me because of its functionality. I recently widened an internal mag in a Remington 700 to try to house 4 WSM cases (which are .404 Jeffery width) with a PTG canoe floorplate. Sure, I can fit 4 in, but they just won't feed and jam at the extra width going up the feed ramp at a wider angle, so I had to go back to 3 in the narrower internal magazine so they would feed.

RH,

I’ve found that the Ruger Hawkeyes need to have the feedramp widened, specifically opening the ramp angle slightly to allow smooth feeding of flat nosed solids.

Wildcatter, I'll have to look carefully at the Remington to see if I can possibly widen the feed ramp...I very much want to fit 4 WSM's in the internal mag with the canoe floorplate. When you say widen, I assume you mean flatten out the curvature on both sides? Riflecrank, perhaps consider calling your Ruger "Violet" in view of the stock. One wouldn't want their rifle to always be living in the shadow of another rifle with the same name.

RH,

you’re correct.

I mean taking the curve of the feed ramp outwards into the corners. Have to be careful not to produce an overhang that can hang up the bullet nose. Taking care to keep a curvature at the lateral angles helps keep the nose of the bullet aimed centrally. This is probably less of an issue in the Remington PF as the cartridge should be freed from the mag into the center of the feed ramp. However, I can’t say that with certainty as I don’t have experience modifying Rem actions for WSM cartridges.

Sir Ron,

Thanks for the refresher course on Mauser mag box width calculations. Solving the equation for magnum-case and 375-Ruger-based-case cartridges, the width would work out to 0.993” to fit the 4th cartridge. IIRC I measured Gene Simillion’s mag box in my 460 G&A, which takes 4 rounds in a flush stock, so I’ll need to check how well it fits the formula prediction.

Sir,
I resemble that remark. My maternal grandmother was named Violet.
Poor lighting has confused your appreciation of black web on red.
That is my color coding for Ruger and Winchester B&C stocks.
I use grey web on black for Mauser M98 rifles.
Not shown here is the black web on green or solid black, my two choices for CZ 550 Magnum color coding.
Heh-heh-heh:

Well that makes it easy...."Ruby". Ruby Ruger.

Well that might work.
My Wife's maternal grandmother was named Ruby.
I don't think she would mind.
My typo: I meant red web on black.
My Aunt Marcella was a sweetheart and a redhead.
My red on black Winchester M70 Classic .458 WM+ is named Marcella.

Resetting priority:
No new .458 Winchester Magnum Dakota (.458 WMD) reamer
until there is a new .458 Winchester Magnum Ruger (.458 WMR) reamer.
No more re-chambering of a ringed chamber to .458/.416 Ruger Winchester Magnum Throated with multiple reamers.
Starting with a virgin barrel.
Her first name will be Ruby.
Last name Ruger.
No accident this time.

Well congratulations on Ruby Ruger, a splendid name. I wonder whether you intend to baptize Ruby (perhaps crossing a river on horseback or quad in Alaska on a bear hunt)? Yesterday I got the 4 WSM rounds to fit in (by using shims) and feed (by narrowing the top of the internal mag. box). I 'll post 83 gn .450 loads when I test them in a few weeks.

Good work, Riflehunter.

I noticed this, since my last session with the .458 WinMag,
with three .458 WinMag rifles I fired at same session,
from clean, cold barrel, the rising velocity as the barrel gets nicely fouled,
and your data:

"At the muzzle (with my new Garmin) with a cold, clean barrel with 78 grains of H4895 and 500 grain Woodleigh I obtained:

1929, 1904, 2018, 1964 and 2062 fps

to give an average of 1976 fps out of the 25" barrel with Federal Mag 215 primers. This was a very pleasant mild load. I will measure 83 grains H4895 next session and hope that is around 2100 fps, and if so, that will be my practice load."


Be sure your barrel is nicely fouled before shooting for a 5-shot velocity average.
The common easy fouler might take 2 or 3 shots to get consistent/optimized.
Some lesser-fouling barrels might need 10 shots to get optimized,
like the stainless, 5-groove, JES, re-bore on Hammerella the .458 WinMag.
Just my SWAG.