I thought it was finished 2 years ago.
It seems the chamber was ringed by machinery gone fallow while the smith was trying to do medical school and gunsmith on the side.
The oil sludged up in the system (biologocal contaminant growth?) and instead of flushing the chips out of chamber during the reaming ...
well just a guess between the medical student smith and I.
He is a talented guy, but in 4th year of medical school now, too busy for me to bother him ...
So I turned it over to Rusty McGee and in 2 weeks the 25" barrel got chopped to 23" "featherweight" by the time it was done.
Bead blast removed the former baked on paint, matte blued now, Pac-Nor stainless barrel nicely dulled.
It is a 1:9" TWIST.
Rusty installed a LaPour safety, then filled in the now gaping barrel channel with Marinetex.
Next?
A CZ Kevlar stock might lighten this 9.5 pounder a few ounces?
Or I could remove the hump on the hogsback to a straight comb,
then bob the forend and install a rod in the grip and a grip cap.
But this very plain wood is not that appealing to me, and the hogsback fits me well as is, for initial shooting.
So I think B&C Kevlar from CZ, it shall be, one of these days. It's in the queue.

How the first 500 Mbogo performed on cape buffalo with a light load of 450-grain GSC HV at 2654 fps (not FN as I misspoke):

Ron Shooting A Buffalo

The proper load with the 450-grainer uses 10 more grains of Benchmark and gets 2835 fps in a 25" barrel.
A powder that fast should lose very little velocity in the 23" barrel.

A 9 twist?
Are you trying to make the bullets dizzy?
I guess those 750 grain bullets will be stable in game
Yeah my vote is for a Kevlar stock

Ron,
Nice rifle!
Bryan

Hey, just fine as is. No need to reduce weight with a 450gr at 2,654 fps! Looks like pure function....I like it!

boom stick,
Reckon the 1:9" twist and 2800 fps will make a .510/450-grain GSC HV open up reliably?

Just to keep this "Homage to Dave Estergaard's 470 Mbogo" alive, please allow me to illustrate, again:





A comparison of the rebated, short-necked 500 Jeffery to the 500 Mbogo perfection, all 3.000" of it: from -0.050" to +2.950" on the ruler













Rusty McGee also added a LaPour safety and a thread protector muzzle cap for 500 Mbogo Rifle No.1, and slicked up the feeding before it went to Tanzania.
That is a removable Vais Brake on the end of the barrel.

The Manson reamer, QualCart brass, and Redding dies worked perfectly on this one.
Redding says they no longer make 50-cal dies.
Hornady will do.

Thanks, Bryan.
You too Biebs.
Rusty McGee cleaned that disaster up nicely.

BTW, ignore the Ammoguide case capacity.
It is actually about 155 grains of water, halfway between the 500a2 and the 500 Jeffery.

Ammoguide case capacities are not real.
They are calculated values using their software.
No matter what you submit as measured for a given make of brass, they only publish a calculated value.
They are consistently wrong on just about all case capacities there.

Anybody know a source for a replacement trigger for the CZ 550 Magnum and Medium?

http://www.midsouthshooterssup...tem.asp?sku=00078550
here ya go, buddy

I have a new shipment of 535 BBW#13 NonCons arriving tomorrow! Hmmmmm!


Michael

quote:

Originally posted by michael458:
I have a new shipment of 535 BBW#13 NonCons arriving tomorrow! Hmmmmm!


Michael

Well time for the 510 MDM
Necked up Rigby case to eliminate the shoulder no other mods and should have perfect magazine geometry for 416 Rigby conversions.

Thanks, El Jeffeosso!
Timney!
And Mid South Shooter's supply is just down the road from me. I used to walk into their warehouse in Clarksville, TN to buy stuff, before they relocated.
They got tired of me pestering them.

quote:

Originally posted by michael458:
I have a new shipment of 535 BBW#13 NonCons arriving tomorrow! Hmmmmm!
Michael

I have plenty of .510/535-grainers, and know where I can get more.
I need to mail you something instead, like the 5-Issue set of DGH?

Ron,
Great video! I really enjoyed it. As far as the .500 Mbogo, uh, I think I'll take a rain check on that one.
Max

quote:

Originally posted by prof242:
Ron,
Great video! I really enjoyed it. As far as the .500 Mbogo, uh, I think I'll take a rain check on that one.
Max

A .395 would have done just as well,
and one time in Tanzania I wished I had grabbed the .395 instead of the 500 Mbogo when setting out for a stroll after buffalo.
His name was Chester and he got away.

quote:

Originally posted by RIP:

quote:

Originally posted by michael458:
I have a new shipment of 535 BBW#13 NonCons arriving tomorrow! Hmmmmm!
Michael

I have plenty of .510/535-grainers, and know where I can get more.
I need to mail you something instead, like the 5-Issue set of DGH?

Well, tell you what, I will borrow the DGH, just long enough to look through them, and send them back to you! How's that work for ya?

Michael

Doc M,
I'll get the set in the mail to you tomorrow. Keep it!
Letter Rip

Thanks RIP, I will be on the look out.
M

What are the blue, potentially pointy bullets up above?

Is anyone trying to duplicate the 430 grain .500" CEB tangent?-HP (.426 BC) in .510", perhaps at 440-460 grains? That .500" bullet was a pretty design and just calls out for a .510" twin. Mbogo, AccRel, Jeffrey, and Asquare would all benefit.

quote:

Originally posted by 416Tanzan:
What are the blue, potentially pointy bullets up above?

Is anyone trying to duplicate the 430 grain .500" CEB tangent?-HP (.426 BC) in .510", perhaps at 440-460 grains? That .500" bullet was a pretty design and just calls out for a .510" twin. Mbogo, AccRel, Jeffrey, and Asquare would all benefit.

Tan,
Those are blue molly coated .510 450-grain GSC HV bullets.

quote:

Originally posted by capoward:

quote:

Originally posted by 416Tanzan:
What are the blue, potentially pointy bullets up above?

Is anyone trying to duplicate the 430 grain .500" CEB tangent?-HP (.426 BC) in .510", perhaps at 440-460 grains? That .500" bullet was a pretty design and just calls out for a .510" twin. Mbogo, AccRel, Jeffrey, and Asquare would all benefit.

Tan,
Those are blue molly coated .510 450-grain GSC HV bullets.

How do those moly bullets clean-up? I've seen but never used the old Barnes aqua-coated moly X-bullets. apparently they changed to multi-groove without moly because of complaints.

Incidentally, Custom brass and bullets says that they will soon be getting/ordering GSCustom bullets without moly.

quote:

Originally posted by RIP:
Anybody know a source for a replacement trigger for the CZ 550 Magnum and Medium?

I was thinking of suggesting a replacement trigger after looking at your nice rifle.I remember what my CZ trigger was like before Ralph Martini replaced it.I never could have it break the exact moment I wished.Sometimes it broke too soon while othertimes it would almost not break at all.My Ruger trigger is consistant but a little factory heavy,not the best for quick accurate shooting.The timney Ralph installed is dream like.It is not too light or too heavy and has no slack.IMO,no matter how nice a rifle one has it is nothing if it doesn't have an excellent trigger.Having a great trigger might not be the trigger itself but who installs it.The fine trigger on my CZ is one of the reasons I had Ralph build me a custom rifle.

shootaway,
Good to hear the Timney trigger worked well.
I have one now, "CZ 550 Magnum Item #555."
It was the last one in stock at Midway, backorder-able now.
I got it there because it was not a clearance trigger at the other place.

The blue bullets above are the old Barnes XLC .509/570-grain, flat based with a cannelure.
The coating is something they claimed was also used in race car engines,
for friction reduction, higher performance, and longer life of engine parts.
It was the Barnes idea before they went to TSX bullets with multiple cannelures for less bearing surface.
We still jokingly call them "Smurf bullets."
They foul very little.
Good for making "Smurf dummies."

Well that was a big on my part...totally forgot about the Smurf bullets.

Nice rifle, great round. I would take a rasp & sandpaper to the stock, ebony tip, rechecker, etc., otherwise very nice.

Forrest,
Thanks.
I have a physiognomy that makes the CZ Lux "Hogback" stock fit me perfectly if I just get the LOP up to 14.5".
All that wonderful beautification work you suggest would be wasted on me, since "Kevlar" is where my heart is.
I'll shoot it like it is, with a slip-on pad, for a while.
A double recoil pad is always helpful with a 9.5# 500 Mbogo.

If I ever need to rechamber, rebarrel my A2 (very unlikely) it will be the Mbogo. If I had it to do over, it would be the Mbogo. Not much difference, but a superior design never-the-less.

quote:

Originally posted by fla3006:
If I ever need to rechamber, rebarrel my A2 (very unlikely) it will be the Mbogo. If I had it to do over, it would be the Mbogo. Not much difference, but a superior design never-the-less.

Yes, it is a stunning design.
For the .510" one only needs to choose the power level for three superb designs:
for 7000 ft lbs, use the 2.65" 500 AccRel
for 8000 ft lbs, use the 3.0" 500 Mbogo
for 9000 ft lbs, use the 510/505 Gibbs.

Those three are the nicest .510's one could imagine. For a light, smaller rifle, the first in the list is a great design.

No.2 Rifle: 23" barrel, 1:9" twist, 58 degrees F, 105 grains of Benchmark, 450-grain GSC HV: 2563 fps average.
That is a starting load for the 500 Mbogo.
It is the one that killed the cape buffalo with one shot from No.1 Rifle.

No.1 Rifle: 2654 fps in the 1:10" twist 25" barrel previously, with same light load. 2835 fps with 115 grains Benchmark, max load.
So if the same velocity change happens with the max load in No.2 Rifle, 2563 +181 fps: 2744 fps, estimated.

I think I would rather load it with 570-grainers at 2150 fps and tame it down to 500 NE velocities for more enjoyable shooting.

Talley ring trouble on a CZ again:

I stripped out a set of Talley rings today.
My fault, I tightened a QD lever too much.
On the fifth shot my little Leupold 2.5X came loose in the rear ring, front ring still held.
One more shot and the scope would have gone ballistic.
My first clue was when the bullet impact went from dead-on zero at 50 yards to impact 8" northeast of zero.

I have a solution: Homemade QD levers on standard CZ rings.
I drill and tap a Leupold QD lever for an automotive metric screw that fits the CZ ring base, screw them together and epoxy the QD lever onto the automotive screw.
Then you can finger tighten or use a 5mm hex bit and torque driver to torque to 65-inch-pounds as CZ recommends for their main ring screw, what they call the "Clamping Screw."
This is a more robust screw than either Warne or Talley use.



There is no stronger setup for a factory CZ integral base with solitary recoil lug on rear ring, for solitary recoil slot on left rear receiver.
Having the horizontal split ring is better than a vertical split ring, if the clamping screw affects the vertical split.
Warne vertical splits seem to be immune from this problem, but they suffer the "two-screw-holes" problem in the recoil lug of the CZ rear ring.

Here are the lever sides of the "CZ-home-boy-QD" with a 2.5X Leupold Ultralight 1" tube,
and the Warne QD rings with a Weaver Grandslam Dangerous Game 1x-5x 30mm tube:





I'll use the Heavier scope and Warne rings on something gentle like a .395 Tatanka CZ.
I am also using the heavy Weaver DG 1x-5x on a 404 RIP Dakota M76 with Talley 30mm rings,
ON TALLEY BASES, AND THEY OFFER A DOUBLE RECOIL SHOULDER.
That cartridge is also more gentle on scopes than the 500 Mbogo.

"Scope lightly and carry a big kick and you shall go far."
Theodore Roosevelt, from The Happy Hunting Ground.

Cool ring modifications Ron...

Slick way of solving a problem.

Love both of your 500 mbogos espciallt No.1.

Regards,
Dave

Dat rifle Berry Berry nice, Ron!

DavidC and tiggertate,
Tanks! It is a work in progress.
Now that I have replaced the mangled Talley rings, I go back and shoot for chrono/accuracy at 50 yards with 2.5X Leupold.
I will load some 535-grain S&H brass FN solids for nostalgia-sake.
Eventually will work up to 705-750-grainers at 1000 yards.

Another thought: with a 1:9" twist I might be able to use some 770-grain cast boolits (or any BMG target bullet) at subsonic velocity for plinking.