I was doing some reading on this cartridge and found a funny story about it I'd never read before. Thought I would share.

Around 1960, Fred Barnes built himself a 475 A&M-chambered rifle, based upon a sporterized Enfield action. With its open sights, the rifle weighed no more than 8 lbs. Being Fred Barnes, his initial handloading effort combined stiff charges of IMR 3031 behind his 600-grain bullets. He, friends and a small group of well-wishers went to an informal shooting range near Grand Junction, Colo. Fred sat down on the pea gravel of the parking area and crossed his legs to fire from the sitting position. He took dead aim at the base of a small juniper tree, which was tenuously hanging on at the top edge of a roadway cutbank.

When Fred pulled the trigger, everyone was watching for the impact. The shot went low. The tree was summarily uprooted! All watchers cheered as the tree fell, then, as a group, they looked around to find what Barnes' reaction might be. There he was, located several feet behind his original position, lying on his back, arms outstretched, holding the rifle above his head. Dust from the muzzle blast and his ignoble recoil-induced slide (he had absorbed well over 110 foot-pounds of energy) was still stirring when Fred asked, matter-of-factly, "Anybody want to buy a rifle?" He found no takers.

Thought this little anecdote was pretty humorous. It seems like someone on these boards said they had a rifle chambered for this cartridge. I would love to hear any experiences and or insights anyone might have. Being that it's a 378 Wby case necked up to .47 caliber, it would definitely pack a punch. Chat away...!!

I don't know that the velocities quoted in cartridges of the world are realistic, but it is still impressive.

470 Mbogo is actually a bigger/badder number than the .475 A&M, the latter having been greatly exaggerated in the literature of the past. Still, 8 pounds is about 2.5 pounds too light for such a rifle.

A mere pipsqueak for the Dinosaur rifle nuts around here.

The AhAhA&M and MaMaMbogo aren't big enough
for us guys that have soaked up rrrreal
reeeecoil.Ed

Ok, I've got one. That "story" is pure BS. The velocity and energy claims are BS as well but it sure is a funny visual image. It will do just about the same as the 470 Mbogo. I can get 2500 from both with a 550 gr FN solid but you could go faster with the Mbogo than the 475A&M. There is just a bit more case capacity but not enough to worry about.

If you think about it', it’s between the 460 Wby and the 500A2 so recoil has got to be in between the two given similar rifles.

RIP is right on. Put it in a 10-11 lb gun and it's really a shoot able cartridge and it will put the hurt on anything it hits.

I’ve still got the reamer for it and the Mbogo and may be making another one of each for a friend later this year. I got dies from CH4D and good loads were very easy to find. The rifle I have seems to shoot anything well.

John

"A mere pipsqueak for the Dinosaur rifle nuts around here" Who me ?

^^It doesn't surprise me that it's B.S. I've never shot anything in the big bore realm, so I am easily amused.

It is a 378 Wby necked up to .475 cal. and it will get you near 3000 FPS with a 500 gr. bullet with 110 grs. of IMR-3031 or 2500 plus with a 600 gr. bullet with 105 grs of same...and it will stomp you into the ground.

I shot one a few times one day, resting over sand bags and coats over the hood of the bakie, never wanted one for myself after that. Hurt my middle finger so bad I could flip anyone a birdie for months..

Yeah thats is shit, like the people who told me when i was after a .375 H&H many moons ago that it would give you nose bleeds and make trees part when you fired it. My .585 Nyati does not give me nose bleeds.

Cute story, but NO 475 in a bolt gun is more boot than a trex..

the mbogo is my favorite sub 1/2" round, followed by it's pipsqueak buddy, the 376 steyr

as i have personal knowledge that a9.5# mbogo is too light, i can't imagine that that an 8# would be any fun.

the A&M had my attention for 20 years... but the mbogo rocks!!!

jeffe

quote:

Jeffe: the A&M had my attention for 20 years...but the mbogo rocks

What's the difference besides the belt?

I"ve always wanted a 475 a&m. Read the ballistics and now i feel under gunned with my 8.5 lb 458 and my 9.5 lb ruger #1 in 460 wby. Where is the justice in it all..?? god now it looks like i have got to build a bigger rifle in a SERIOUS calibre so that i can feel what REAL recoil is like..sounds like fun to me and if i suffer a detatched retina??? any one know how to fix me up real good???(blond 5.1 105 lbs and a good cook??)

What about a .700 Nitro that weighs in just under 3 lbs? Would that do the trick?

Forrest,
minor things, like some dimensions.. iirc, the mbogo is about 10 gr more h20...

and i know dave, not parker!!

jeffe

I believe the .475 A&M is basically a belted .470 Mbogo using 460 WBY brass. Don't remember wher the shoulder is in relationship to the 460 though. Since I never hit 2700fps out of a 460 wby with 500 gr bullets I doubt 3000fps is doable more than once. My 470MBOGO's will drive a 500gr woodleigh to just over 2700fps. The performance of the .475 A&M was vastly overrated IMHO.-Rob

quote:

Robgunbuilder: I never hit 2700fps out of a 460 wby with 500 gr bullets I doubt 3000fps is doable...My 470MBOGO's will drive a 500gr woodleigh to just over 2700fps. The performance of the .475 A&M was vastly overrated IMHO

I don't see how the A&M could possibly hit 3000fps with 500 grainers. The 378 can't even do it with 300 grainers. The 460 does under 2700 with 500s, my 510 Wells will do around 2500 with 530s, the A&M should be somewhere close.

The 460 is at the end of the road at 2600, at lest in the 460s with the Pendleton Dekickers which would have an effective barrel length of about 24 inchs.

Increasong the bore to .475 and assuming equal pressure and equally suitable powder would add another 50 f/s with 500 grain bullets, maybe 75 f/s if the 475 A&M is an Improved 460

Mike

I got 2685 fps with 500 grainers in my 470 Mbogo, with no pressure signs, using RL-15. Next time I load it I will add that one extra grain of powder to get 2700 fps. The Ugly Rifle with reinforced laminate stock:
5 crossbolts
2 pillars
axial grip rod
stainless steel wire wrapped grip covered with epoxy.
10.75 pounds.

^^RIP, have any pics of this ugly boomstick?

HO HO HO JEEZ HO HO HO!!!

RIP,
it's getting warm enough.. send me your mailing address and i'll send you some bbq flat black to cover up that shiney barrel!!!!

No thanx Jeffeosso, it ain't that shiny being bead blasted stainless that has been through the bluing tank! Besides, the barrel echoes (like thunder and lightning) the aluminum chips accentuating the head of the Hammer of Thor which you see tapping the mbogo on his left horn tip! There is a lightning bolt checkering pattern along both sides of the forend. Left side is perfect. Right side I boogered up in places, covered by the hammer and horns inlays.

I call this rifle "Mjolnir" which is Icelandic for Thor's mallet. I have also seen it spelled "Mjollnir" and there is an oomlah over the "o" in either spelling. Pronounced sort of like "Mule-Near." Kicks mule-near-like too when knocking on the door of 2700 fps with 500 grainers.

Any of our Scandinavian friends with alternate non-English names for Thor's Hammer?
Sumbuddy who know something besides Mjolnir?
Please list.
Thanks in advance.

Never mind youse Vikings. There is no other name for Mjolnir. There can be only one.

"Mjolnir" means literally "that which smashes" or "the crusher."

Odin's magical war spear was called "Gungnir."

What does that mean? "That which pierces," or "the poker?" Pokie?

Is there really such thing as Icelandic language, and are these words from it?

Mjolnir
Gungnir

Hmmm? Sumbuddy who know?

I fooled with a .460 WBY for years. At 2650fps I had primer pockets open up and the brass expand at the belt over .005. That was more than enough for me to quit. I know people who have exceeded 2700 out of a 460WBY but frankly I was unimpressed with their ability to judge what was safe and what isn't. Thus, I do think you might get 3000 fps out of a .475A&M ONCE!
However, picking brass fragments out of my face
for a few hours afterwards really doesn't strike me as a real good idea.-Rob

Hi Gents
I'm in the middle of a computer crash and spotted this thread while on my wife's office computer.
Ray, Ray, Ray I can't believe you quoted those blue sky figures from Cartridges of The World. They are so off base and dangerous,I can't believe they haven't deleted them.
From what information that I've gathered the 475 A&M is just a necked up 460 and not an improved cartridge. The 470 Mbogo should hold 9 or 10 grains more water than the 475 A&M as well as the 460 Weatherby and be minus the belt.
The 470 Mbogo is magic at 2500 fps and keeps the pressures very moderate ( read good brass life).
Take good care,
Dave

k time to practise my ignorance. As i am new here i am not familiar with the 470 mbogo.And living in alberta we are kinda cut off from the real world of big bores. I love my 458 and 416 and 460, so i am not new in the big bore world...BUT... will some one please tell me what the 470 mbogo cartridge is based on? Any info would be greatly appreciated....regards Dennis

icehunter121,
You are cold.
Get warmer by clicking on Dave's link above. He is your countryman and creator of the excellent .470 Mbogo.

108 grains of RL-15 with 500 grain XLC >>> 2526 fps from Mjolnir's 25" barrel.

115 grains of RL-15 with 500 grain Barnes RNSP >>> 2685 fps by Mjolnir.

My 6.75 pound .375 H&H is Gungnir.
My 10.75 pound .470 Mbogo is Mjolnir.

My baby cartridge,458HE gets 500gr out at
2800+ with long barrel, using 135gr of
W-760 or H-414, and at about 50k psi.Ed.

According to Ackleys book, you can get just a tad under 3000 FPS...?????????and the guy that owned the gun I shot, said it chronographed at that. I listed those loads above..As for me I don't guess at these things, nor do I care what it shot, it kicked too much for me to use in Africa under hunting conditions.

I would trust what Rob says about picking brass fragments, maybe rifle fragments, out of someone's corpse if getting 3000 fps with a 500 grainer in the .475 A&M: The Ultimate Singleshot Rifle Load. Something that really does kill on both ends of the rifle.

The .470 Mbogo with 500 grainers at 2500 fps is gentle and effective as Ray's Metamucil.

I've gotten 2700 fps with mine, although with a 550 gr bullet, but that was definitely max as primers were cratered and belt expansion was .004-.005. There is no way to get to 3000fps safely. It is a great 2500fps cartridge but even then it needs more pressure to get there than the 470 Mbogo.

The version I have is a slightly improved version. Less taper and the shoulder is a bit further forward than the 460 wby. Mine also is without that double radius typical of the Weatherby cartridges.

It is an effective case that is shoot able, accurate and powerful enough to be a decent stopper. That said IF I was only able to have one 475 dia rifle it would without doubt be a 470 Mbogo. Basically it gives the same velocities with less pressure and brass can me made from 416 Rigby cases in a pinch.

John

Well, ole P.O. Ackley was stunt pilot without a doubt, but Rip, your such a wuss!

Ray,
A man has got to know his limitations, and the limitations of his "piece."

Has anyone tried the Lazzeroni 12.04 (.475) Bibamufu? It seems Lazzeroni strives to be at the top of obtainable velocities or darn close. He publishes 2800 f.p.s. with his .416. So theoretically 3000 with his .475 should be possible.

Well a .475 on the .600 OK case aught to hit 3000fps with a 500 gr bullet no problem. In fact, I believe 3250 fps or more should be max. Barrel life should be short but what the heck. Fritz 454 did you get a reamer made for this one?-Rob

Rob, I have a barrel for a 475-600 but not a reamer. I ended up boring the 510-600 and 550-600 on a CNC lathe and it worked out great. I will be doing the same on the 600 OK based cases. I have barrels for 458, 475, 510 (already done) and 550 (also done).

I think the 458 will really burn barrels but loaded down with 7828 500 grs @ 2400 to duplicate 458 lott velocities and if you want to run it hot 3300 or more with 414.

I ended up making a 5c collet holder that is trued to the spindle center so I can grab the barrel in a collet on both ends. One in the spindle and the other on the nose. Run out is less than .0002 TIR.

I can thread and chamber in one shot. Takes about 20 minutes to finish both. Switch ends and collets, and threading for a muzzle brake is a snap.

I can use this method for anything .375 or larger. I use the circle boring bars and a carbide insert. One to rough it out and one to finish it. Then run a bit of scotch brite after it’s bored to remove the tool marks, which are minor (the inserts have a .008 radius). Simple.

Rob, if you want me to chamber one for you let me know I'd be glad to do one when I do mine.

John