Questions about 50 caliber (or larger) project rifle

[Big_Easy]

As a left handed shooter I rarely see (if ever) a left-handed rifle in a 50 caliber (or above). However, a used 375 H&H still seems to be fairly common from time to time online. I'm curious as to whether or not I can purchase a used 375 H&H rifle and use it as a donor, and have a custom rifle built in the .50 (or greater) range. Say, in a 500 Jeffrey, 500 A-Square, or a 550 magnum round? Some folks have recommended that I use an existing .416 Rigby action, but those are very hard to find in a left-handed action. So my main question would first be, can I use a 375 H&H donor action, or do I need something larger? My understanding is that it'll come down to the size of the bolt face? If I use a 375 H&H, is there any downside to using it versus a larger .416 Rigby one?

Second question would be which action to choose from? As a LH shooter, the two main ones used for donors that I've seen are the CZ 550, and the Win. Model 70. I've seen some used Dakota 76's, just not that many as of late in LH. Perhaps an old Sako action, or a Ruger? Does it ultimately come down to ones own preference, like when I hear a Chevy vs Ford argument?

Any help for this big-bore novice would be appreciated.

 

[odonata]

As a left-handed shooter, I feel your pain. But as a fellow novice, any advice I give should be taken with a grain of salt since it will be based on intuition not in-field experience. I solved my larger bore problem by rebarreling a LH Ruger M77 MkII from a 7mm Rem Mag to a 458 Win Mag and it was a fun project. The rifle shoots & feeds great since both rifles used the same parent case. Because the 500 A-Square uses a 460 Weatherby Magnum parent case, intuition tells me you could similarly rebarrel a left-handed model of one of their rifles & maybe be able to achieve what you're looking for if you can find something like this:

www.rockislandauction.com/detail/1040/3093/left-handed-weatherby-custom-mark-v-rifle-in-460-wby-mag

One item to check with any rifle will be if the 375 H&H bolt face can be enlarged to the 50 caliber base size. Google shows that at least one person has done this with a CZ 375 H&H conversion to 500 Jeffery. I'm assuming the left-handed nature of a donor rifle would have no bearing on this and that a conversion would work equally well for R or L. I would also guess that additional work to the follower may be required to get it to feed properly:

This has absolutely nothing to do with your question so I apologize for the tangent in advance. But if you were looking for a rare LH African rifle, then buying this one next month as an alternative would save me from temptation & would be a big favor:

www.rockislandauction.com/detail/4093/3441/american-hunting-riflescz-model-550-lh-safari-magnum-rifle

 

[AZDAVE]

Interesting question.

My first response is
1."What is your budget?
Granite Mountain arms makes their double square bridge african express action in left hand.
2. Talk with your gunsmith on the options of new vs Donor actions.
3. For the stock are you looking for a classic wood stock? or a good synthetic?
a. If wood is your gunsmith doing the fitting or a custom stock maker?
b. Cost can get KRAZY depending on the grade of wood you select.
4. Rifle fitting is critical in a 50 cal or bigger!

Make sure you lay out your requirements and budget and have fun with the experience of building a a big bore.

 

[K-man]

Before someone else chimes in, have you looked at the Blaser R8? Left is simple, get a 505Gibbs barrel, go hunt. Maybe not what you were asking, but a thought.

 

[Riflecrank]

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.

 

[Riflecrank]

Getting a 50-cal or bigger built on a make-do action is not the easiest thing
or least expensive thing to do.
Getting it to feed, eject and retain cartridges properly requires expertise and
cartridge-specific, well-fitted parts.
Easiest thing to do, besides a religious conversion to .458 WinMag (cures BES)
would be a Weatherby Mark V with an in-line vertical stack magazine.
With the drop floor plate from the custom shop you can get 3-down +1 in chamber
with a .500-A-Square, or even Neal Shirley's .550 Magnum if your BES is that bad.
That is the format of Weatherby's DGR rifle in a .416 WbyMag I have.
I have done this with my .500 Bateleur wildcat using the .510/.338 Lapua Magnum Improved,
having a 2.7" case length and room in the Mk V magazine to load some long-ogived bullets,
like 647-gr BMG bullets for plinking.
Fail-safe feeding is assured by in an in-line stack with the feed lips on the Mk V magazine.

 

[Riflecrank]

Get thee behind me Satan !

 

[Big_Easy]

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.

@Riflecrank
Thank you for the entertaining information. Sadly I'm afraid that I do in fact have BES, and that my religious conversion is going the other way. I had a LH Wby Mark V in 458 Win Mag that I ended up selling a few years ago, as I felt it was underpowered (plus, I can always buy a LH 460 Wby. if need be).

I see that you haven't really converted to the 458 Win Mag faith just yet my friend, not until you dispose of either your 500 Jeffery, or one of your 500 A-Square rifles. Specifically to me. I must take one of those off of your hands so that you may further your path to true 458 Win Mag enlightenment. It's ok that they may not be Left-handed, as I grew up shooting my dads right handed rifles. Since the 500 Jeffery is a weird joke/conversation piece, let us start by relieving you of that one, and get you closer to true enlightenment...price TBD...Amen.

 

[Big_Easy]

View attachment 645274

View attachment 645275
Get thee behind me Satan !

@Riflecrank
Sadly, it appears that the Mark V DG and Safari versions have been discontinued on their website, hopefully it's only temporary. Right now they don't even offer the 460 Wby in a LH version in the regular deluxe model on their website. Their custom shop isn't what it used to be either.

 

[Altitude sickness]

@Riflecrank
Thank you for the entertaining information. Sadly I'm afraid that I do in fact have BES, and that my religious conversion is going the other way. I had a LH Wby Mark V in 458 Win Mag that I ended up selling a few years ago, as I felt it was underpowered (plus, I can always buy a LH 460 Wby. if need be).

I see that you haven't really converted to the 458 Win Mag faith just yet my friend, not until you dispose of either your 500 Jeffery, or one of your 500 A-Square rifles. Specifically to me. I must take one of those off of your hands so that you may further your path to true 458 Win Mag enlightenment. It's ok that they may not be Left-handed, as I grew up shooting my dads right handed rifles. Since the 500 Jeffery is a weird joke/conversation piece, let us start by relieving you of that one, and get you closer to true enlightenment...price TBD...Amen.

It’s like a 12 step program. You can not claim sobriety from the 500’s if you still own them. In a moment of weakness you may fall off the wagon.

To claim fealty to the .458 you must renounce and remove all 500’s and above from ownership. Otherwise your just a 500 guy in denial

 

[MLindsay]

The easiest thing to do is get a BRNO 602 and make a 500 A2. Fireform 460 Weatherby brass, feeds perfect
SIMPLE!

 

[Riflecrank]

Big_Easy,
I know just where you are coming from.
I was you, 40 years ago.
I really do not want to encourage your BES, but I might part with one of my relics of insanity
for only $10,000 (USD 10K) if you are a greater fool than I.
I might be able to buy a pristine Pre-'64 M70 African with that amount if I am lucky, or build 4 or 5 more rifles chambered for .458 WinMag.
That would ease my conscience for contributing to your BES.

I should show you some details in order to facilitate:

My first two "fifties" above, basically .500 A-Squares trying to be called something else.
John Buhmiller was first, sometime in the nineteen-fifties.
That is the take-off barrel for the .510 JAB, oiled and plastic wrapped.
I could let that barrel go for a mere 5K USD.
Another view:

 

[BeeMaa]

I'm with @K-man on this one. Blaser R8 in 500J with your choice of how you want it stocked...wood, traditional synthetic (professional) or thumbhole (professional success). I know the image below is RH, but you get the idea.

 

[Riflecrank]

 

[Riflecrank]

Continuing with items for sale for only 10K USD:

Above are some dummies to compare the .500 Bateleur to the .500 Jeffery, fired in this rifle, sale priced at only 10K USD:

Above is the second .500 Bateleur, easily rebarreled to .510 Just A Buhmiller.
As a package deal, on both .500 Bateleur rifles for 20K USD, I'll throw in the .510 JAB barrel for free.

 

[Riflecrank]

For the BES curious who have some reason (locality or personality related) for not going all the way to 50-bore, here is a 49-bore, the 12.7x68mm Magnum.
Offered at only 9K USD for the Winchester M70 Classic. For only an extra 1K USD I'll throw in the take-off barrel for the BRNO ZKK-602 that was also chambered for 12.7x68mm Magnum (.500/.338 Lapua Magnum Improved) at one time. Vais Brake not included, just the thread protector.
Vais Brakes are getting hard to find.
The Vais Brake fits several of my 50-bores, specific to them in fact.
It is slightly more efficient on a 50-bore than on a 49-bore, just a make-do on the 49-bore.

The first five shots fired at 50 yard target from the M70 Classic with 430-gr/.500-cal. CEB MTH bullet:

A subsequent check out to 300 yards with a lighter and faster bullet in the BRNO ZKK-602,
called Rifle No. 2, the (with ballistic-tip) 360-gr/.500-cal. CEB ESP Raptor, which can be used in reverse and without the tip as a 350-gr brass FN solid, like a little football/beer keg:
2903 fps 5-yard chrono, +2900 fps MV. Oehler 35-P at 5 yards from muzzle.

Back to rifle No. 1, M70 Classic, with 500-gr /.500-cal. CEB Safari Solids at a mere 2473 fps for 5-yard chrono, makes this darn close to 2500 fps MV, and the 50-yard targets ain't bad:

Now mind you, the bolt faces of both rifles started off as .375 H&H size and were opened up to .416 Rigby size.
If you are going to build a .500 Jeffery, the .416 Rigby bolt face is too big for the rebated rim of the .500 Jeffery, being about 0.015" smaller than the Rigby diameter.
You should start with a .375 H&H bolt face to open it up for .500 Jeffery.

 

[Riflecrank]

Oops, mixing up my No. 1 and No. 2 rifles.
On the 12.7x68mm Magnum in chronological order, to clarify:

No. 1: Winchester M70 Classic came first and stuck.
No. 2: BRNO ZKK-602 came second and got re-barreled to 10.4 Spiridon Moor deer rifle.

My confusion could be due to my CTE. I hope not. No cure.
There is hope for BES.

 

[Riflecrank]

CTE prevention while suffering from BES, a mental health update:

I figured out that most of the recoil was from the bullet weight pretty much from the outset of my BES in 1984.
Hence here I am in early 2001 before my first African safari:

The best loads of my "sessions":

Note load data supplied on targets above.
Three-shot groups are sufficient to get an idea of 100-yard accuracy with a 577 T-rex load.
Five shots is TMI, hard to concentrate on the fourth and fifth shot ...

This did toughen me up a bit. The .416 Rigby and .375 H&H which I took to Botswana were like BB guns in comparison.

 

[Riflecrank]

My first clue to CTE prevention came from the .500 A-Square shooting 750-grain Hornady A-Max
and 700-gr AP "Black Tip" bullets at about 2200 fps, versus the 570-gr XLC at 2500 fps:

My final mental health measure was the .500 Mbogo 3-Inch shooting 450-grainers at +2800 fps:

Don't laugh about a 450-gr/.510-cal. bullet, even when slowed down to 2650 fps for accuracy and comfort:

Gotta say the 570-grainer at 2400 fps was similarly comfortable and effective from the .500 A-Square,
used with open express sights at 50 yards, no muzzle brake, prevents Weatherby Eyebrow:

 

[Riflecrank]

.500 Mbogo rifles for sale, No. 1:

Harry McGowen himself (or his minions) made this barrel for me before he sold to the new folks in Montana. The dognut on the barrel is where the integral rear sight base is on the CZ 550 Magnum barrels, and yes, he was making barrels for CZ-USA at the time.
The gunsmith did the weird snakeskin finish and cerakote band around the muzzle end of the barrel ...

The Stock is a laminate from a CZ 550 Magnum .416 Rigby, Fat American style.
Reinforced like so:

And the magazine box was also reinforced with steel soldered to front wall:

This rifle is being restocked with a B&C Medalist. Good fit, like on the next rifle, .500 Mbogo No. 2:

Mbogo No. 1 has a 25" McGowen barrel of 1:10" twist, CZ 550 Magnum.
Mbogo No. 2 has a 23" Pac-Nor barrel of 1:9" twist, CZ 550 Magnum.
Take your pick.
Only 10K USD each, not including scopes/rings.