Questions about 50 caliber (or larger) project rifle

[Riflecrank]

My final offering will be sold at a discount, only 8K USD.
This is a .500 Jeffery made from a CZ 550 Magnum .416 Rigby action.
This was done because the action is an amazingly slick feeder of the .500 Jeffery, for whatever reason.
The bolt hardly ever overrides the rebated rim of the .500 Jeffery.
Ejection is sloppy but positive since the true Mauser claw is drawn inward on rearward traction of the bolt. Work the bolt fast and hard and you will eject !
The stock is the cast-off laminate from the first .500 Mbogo.
The barrel is a very fat Light Target (straight taper) McGowen cut to 24" length, 1:20" twist, with a secondary recoil lug on the barrel.
Stock got paper thin on fore end top edges whensanded out for the fat barrel,
so I built it up with epoxy.
Never fear, I plan to sand the rough areas of fore end topside down to smooth and then paint the whole stock with grey truck bed coat, textured.

Again, Vais Brake, scope and rings not included. Thead protector included.

The antique 1:20" twist will be good with cast bullets.
The chamber was done with a Dave Kiff PT&G reamer that adds 0.25" length of parallel-sided free-bore to the C.I.P. .500 Jeffery homologated "no-throat" chamber.

The set trigger and safety of the standard CZ 550 Magnum remain as OEM.
Good for BPCR match shooting.
Indeed, the .500 Jeffery is a close equivalent in case capacity to the 50-140 Sharps.
Use this rifle with duplexed BP and paper-patched bullets for even better performance than the antiques.
Or the easy way is powder-coat-painted, gas-checked, BHN-25 cast bullets.
Some ideas for a start on .500 Jeffery/50-140 Sharps nostalgia.
The Really Big Fifty.

777-grainer works even better in a 1:20" twist.
In the 1:10" twist .500 Mbogo it was slowed down to 1800 fps for slower spin rate but could only do about 2-MOA.
I expect much better from the ".500 Jeffery Match" with 1:20" twist.
Haven't tried that cast load yet, but this rifle has been in the works since 2003 when I was still BES afflicted.
Make me an offer ?

 

[Riflecrank]

The reason you need to use a .375 H&H bolt face to open it up to .500 Jeffery rim size:

 

[Riflecrank]

Collect this reward then buy my 50-cals:

 

[Riflecrank]

Did MRC ever make any left-handed PH actions ?

That action has a +4.00" magazine inside length and
bigger bolt diameter like the Granite Mountain big action.
Good one for the .505 Gibbs.
I almost did a .510/.408 Chey-Tac.
I did the .408 Chey-Tac as a 10-pound sporter:

Barrel fluting cut a lot of weight off the Lilja No. 7 (!) Sporter Contour.

I would certainly rather have a .510/.408 Chey-Tac than the stodgy old .505 Gibbs.

You guessed it, .408 Chey-Tac for sale, only USD 10K.
Scope and rings not included.

 

[colorado]

Yes, the 500 Jeffery can be built on a standard M98 action, or a Winchester M70 LA, RH or LH.
I have .510 caliber wildcats built on both of those action
(FN M98 with Duane Wiebe .500 Jeffery bottom metal
and M70 Classic RUM action with Sunny Hill drop floor plate in McMillan stock designed for it).
Both of those use the .416 Rigby or .338 Lapua Magnum bolt face.
But ...
Do you have a .458 Winchester Magnum ?

Here is what I said to one person recently who scoffed at the .458 WinMag:

"Bless your heart.
You either have a case of Bore Envy Syndrome (BES), which is akin to an inferiority complex,
or Chronic Traumatic Encephalopathy (CTE) if not low IQ before you even pulled a trigger.

A good psychiatrist can help you with BES, but those are hard to find, as most shrinks are crazier than their patients.
They do prescribe drugs, and you might get lucky and get some help from the right medicine, if the side-effects don't make you worse.
Sometimes the only real treatment for BES is a religious conversion.
Have faith in the .458 Winchester Magnum and you will overcome your delusions of grandeur.

If you have CTE it will only be confirmed by autopsy of your brain to include microscopic studies.
But the treatment is just the good, clean living and a good social support system, like we all should strive for.
Will your family take you back in when it gets tough to care for yourself ?
Relying upon the .458 WinMag for elephant hunting instead of a .458 Lott or bigger bore
has been shown to slow the progression of CTE.

Low IQ: Most morons can choose to be happy, and a few idiots too.
Get a .458 WinMag and be happy."

I must confess that I own many rifles more powerful than the .458 WinMag.
Among them a .458/.416 Ruger WM-Throated, .458/.338 Lapua Magnum Unimproved, 470 Capstick, 470 Mbogo, 12.7x68mm Magnum, .505 Gibbs, .500 Jeffery, .500 Bateleur, .500 Mbogo, 20ga From Purgatory 3.5" (aka .615 NE), 12ga From Hell 3.85" (aka .730 NE).
That last one knocked my socks off with a 1400-gr conical slug at 1800 fps, and it can be loaded to higher MV, no thanks !
Do the .408 Chey-Tac, .416 WeatherbyMag, .416 Barrett and .50 BMG count ?
When you have BES they do !
Notice I did not mention my one .458 Lott, made by re-chambering a .458 WinMag,
since it is only of same level as a .458 WM+.
The SAAMI .458 Lott is less powerful than the .458 WM+.
.458 WM+ loads may be fired in any SAAMI .458 WinMag but may be unsafe in a SAAMI .458 Lott.
I have been cured of BES by my religious conversion to the .458 Winchester Magnum Faith.
When the chips are down I would want nothing other than a .458 WinMag in my hands.

Now, anything other than a .458 WinMag is just a toy for me.
I confess it took me 21 years to assemble a .500 Jeffery starting with a set of handloading dies purchased in Rapid City, SD when I was just passing through town
in a delirious state of BES.
I realized what a weird duck the .500 Jeffery was and finished it up as a joke, a conversation piece.
Like for this conversation right now. Heh-heh-heh.

Live long and prosper and don't get CTE.

PS:
Forgot to mention the two .500 A-Square rifles I had built in 1999.
And the .450 Barnes Supreme I had built in 1987.
And the 460 WbyMag MK V purchased in 1984,
and another 460 WbyMag "custom" BBK-02 I had built in1993.
I converted to the .458 Winchester Magnum Faith as a true believer in 2017.
That was 33 years (1984 to 2017) before I was cured of BES.
Amen.

Big bores start at .500

 

[Riflecrank]

Big bores start at .500

Baloney.
Big bores start at .458 WinMag.
Even my 470 Mbogo is a "big bore."

"Beware the man with a .458 WinMag. He is more deadly than anybody with a bigger bore."

 

[grand veneur]

According to John Taylor, when it comes to cartridges for hunting big game, big bore cartridges are primarily cartridges caliber 458 and above. According to Arthur B. Alphin, If you take all cartridges into account and also the rifles for it, you will be talking about a heavy rifle from caliber 40 onwards, but there are certainly other classifications.

 

[Riflecrank]

Both in 10.5-pound rifles, free recoil calculated :

500 Jeffery 600-grainer at 2300 fps with 108 grains of RL-15: 107.7 ft-lbs @ 25.7 fps

470 Mbogo 500-grainer at 2700 fps with 115 grains of RL-15: 108.0 ft-lbs @ 25.7 fps

Near identical recoil.
470 Mbogo beats 500 Jeffery by 0.3 ft-lbs. in same weight rifles.
Why do I even need a 500 Jeffery if I have a 470 Mbogo ?
I can only hope it is due to the dying embers of BES and not the beginnings of CTE.

My 11-pound 500 Jeffery is a kitten compared to my 10.5-pound 470 Mbogo.

 

[Riflecrank]

Offered for only 10K USD, re-barrel or re-bore to whatever suits the BES before you get CTE,
or keep it as is and use same loads (same powder charge and bullet) as with your 470 NE double rifle,
and save on wear and tear on the DR: