Grandma wishes all you big bore nuts a
Very Merry Christmas
and a
Happy New Year.
This pic is her X-mas card to y'all.

.308 Lapua-Chui
.338 Lapua-Simba
.375 Lapua-Nyati
.423 Lapua-Kifaru
.458 Lapua-Tembo
.510 Gibbs-Bibi

Max COL for all six of these is 3.800".
The Big-Five-Critter Lapua cases are around 2.700".
Grandmother Gibbs' case is 3.010" max, trim to 3.000".

"Bibi" is Swahili for "Grandmother."
Pronounce it like the .177 caliber shot,
BB.

Grandma's namesake cartridge is:

The Mother of All Buffalo Bashers.

("BBBruce" is "Grandmother Bruce" in Swahili.)

Peace on Earth Good Will to All.

.

Alf,
Thanks for the honor of your reply.
I don't smoke, but I do have it narrowed down to the "Big Five plus Grandma" in Swahili.

Good luck with the mountain lion. Don't go climbing into any trees or trying to wrestle with them. Use that .275 from solid ground.

Now let us go eat the cookies and drink the milk left out for Santa. God rest ye merry gentleman, let nothing you dismay.

quote:

Originally posted by RIP:


Grandma wishes all you big bore nuts a
Very Merry Christmas
and a
Happy New Year.
This pic is her X-mas card to y'all.

.308 Lapua-Chui
.338 Lapua-Simba
.375 Lapua-Nyati
.423 Lapua-Kifaru
.458 Lapua-Tembo
.510 Gibbs-Bibi

Max COL for all six of these is 3.800".
The Big-Five-Critter Lapua cases are around 2.700".
Grandmother Gibbs' case is 3.010" max, trim to 3.000".

"Bibi" is Swahili for "Grandmother."
Pronounce it like the .177 caliber shot,
BB.

Grandma's namesake cartridge is:

The Mother of All Buffalo Bashers.

("BBBruce" is "Grandmother Bruce" in Swahili.)

Peace on Earth Good Will to All.

Hmmmmmm?!? The BiBi would EASILY fit into my CZ's magazine! How long is the throat on the reamer?

quote:

Originally posted by woodsracer:

Hmmmmmm?!? The BiBi would EASILY fit into my CZ's magazine! How long is the throat on the reamer?

Woodie,
That's the idea.
A CZ 550 magnum can handle this with no magazine alterations.

With .505 Gibbs brass length trimmed to 3.000" and necked up by only 0.004" or 0.005", and the bullet crimped on the XLC cannelure (about the longest nose portion you will find on any .509 or .510 caliber hunting bullet), the COL of the pictured dummy is only about 3.775"

If I did not shorten the .505 Gibbs brass by 0.140" from 3.150" max, the same bullet would make the COL over 3.9" which exceeds the box of the CZ or Dakota 76 African (both 3.85").

Granted, some shorter nosed bullets would fit with full length Gibbs brass, but the Gibbs has 0.652" of neck and if I shorten it by only 0.140" I still have over 0.510" of neck length, and that will do fine.

The .510 Bibi has a spec COL max of 3.800".

The .505 Gibbs has a spec COL max of 3.850", but in fact, with the available .505 bullets having such short noses, the loaded .505 Gibbs rounds are usually 3.700" COL or less: a lot of buried bullet wasting case capacity, which the Gibbs can well afford to do.

Throat?
Whenever Dave Manson gets it to HA!/DOA, it will have 0.500" of parallel-sided freebore, and freebore diameter of 0.511", with 1.5 degree leade angle.

This will allow it to handle the Hornady 750 grain A-Max well, and all milsurp bullets.

Make your twist 10" like for the .500 A-Square and .50 Peacekeeper.

The .510 Bibi will do at 40 to 50 KPSI what those two do at 50 to 60 KPSI.

Keep pressures down to 50 KPSI and you can be safe in the usual actions with a rating of 55 KPSI on pressure with Gibbs sized case heads.

Yes, the .510 Bibi will be a buffalo basher and a 1000 yard target rifle.

Grandma wears combat boots.

Rib,
The CZ 550 mag steel metal will NOT work,

quote:

A CZ 550 magnum can handle this with no magazine alterations.

in regards to a gibbs case.

Grasshopper, please do remember proper stagger feed geometery. Improper feeding far worse than rebated rim. At least with rim, when bolt jerked back, round always feed. With improper geometery, bolt jerked back, magizine empties with loaded bullets spilling from top of gun.

Will require 505 gibbs box from CZ, which is VERY much reworked than the 375/416/458 "standard" 550 magbox.


On brass, that's simple, use jamison.

Yes, jeffe,
I know the Mauser cosine-rubber-band-man routine.
I own one of those .505 Gibbs CZ 550's from the factory.

I can tell you that they did nothing special to the box.

It is the same width in front and rear as the
standard .375 H&H box and .416 Rigby box.

This box is best suited to the .404 Jeffery case head diameter according to the Mauser-cosine rule. This is a fact you might take note of for your AR cartridges ... if only they weren't rebated, I would find them interesting.

They (CZ) were originally cutting off the front of the box and moving it forward enough to insert a rubber pad inside the box yet maintain the same 3.85" length, then welding the sheetmetal extension back on.

The latest .505 Gibbs I have seen from CZ had the plain box same as for the .416 Rigby. I measured it with calipers. I did not take the box out of the wood. I hope they welded a steel plate on the front side of the box, hidden, but I doubt it.

The AHR in line feed vertical stack would be best.

Jamison Brass?

I'm the soul who provided Mr. Jamison with the A-square made CZ brass that wouldn't fit in the CZ .505 Gibbs, so he could see what they did wrong and start making his own brass in .505 Gibbs, to fit the CZ, since he was already making the basic case for the .408 Chey-Tac.

I'm the ground floor of Jamison .505 Gibbs brass, I might say. A big CZ dealer and I goaded CZ into scrapping their A-Square made stuff.

The standard CZ 550 Magnum box feeds spitzer and round nose bullets fine in .505 Gibbs, 3 down, no doubt due in part to that reliable big rim (NO REBATE). A little more polishing and it might handle that left sided jam with the FN bullets.

A vertical stack would be neat, however.

There is no such thing as a special CZ-made box for the .505 Gibbs from CZ.

We could all do better than they (CZ) are doing. At least the length of the box is right.

Think about this Jeffe:
A Prechtl made Mauser 98 Magnum actioned rifle I have from SIGARMS is too small in the box width for the .450 Dakota that it is chambered in. So are the Dakota 76 African actions ... by Mauser-cosine rule.

Scary, huh?

quote:

Originally posted by RIP:

.308 Lapua-Chui
.338 Lapua-Simba
.375 Lapua-Nyati
.423 Lapua-Kifaru
.458 Lapua-Tembo
.510 Gibbs-Bibi

RED ALERT!!!

This list fails to mention the completion of this natural progression:

.585 Irascible
.620 Petulance
.700 Enmity

quote:

Originally posted by 500grains:

quote:

Originally posted by RIP:

.308 Lapua-Chui
.338 Lapua-Simba
.375 Lapua-Nyati
.423 Lapua-Kifaru
.458 Lapua-Tembo
.510 Gibbs-Bibi

RED ALERT!!!

This list fails to mention the completion of this natural progression:

.585 Irascible
.620 Petulance
.700 Enmity

Actually Grandma Bibi is irascible, petulant, and full of enmity, so no bigger bore is needed.

Well RIP, I just got (finally) one of Blackburn's 505 Gibbs bottom units and follower. Hole spacing of the CZ is the same as the big mauser but I won't know how close it fits the rest until I get one of mine back. For the price of the AHR single stack one can tinker a lot! If this can be be made to work it will be the nuts for the 510 Bibi.

quote:

Originally posted by tiggertate:
Well RIP, I just got (finally) one of Blackburn's 505 Gibbs bottom units and follower. Hole spacing of the CZ is the same as the big mauser but I won't know how close it fits the rest until I get one of mine back. For the price of the AHR single stack one can tinker a lot! If this can be be made to work it will be the nuts for the 510 Bibi.

tiggertate,
That is very interesting.
Please post the inside-the-box dimensions for width at front (A) and rear (B) of the box.
Pretty please?
And thank you in advance.

You can make a CZ mag box work by staggering the rounds in the box. I weld two steel rods( diameter dependent on caliber( read trial and error) into each corner of the back of the box. 1st round is then positioned slightly foreward, second goes in all the way back and third foreward again. This will work, but is far from optimal. The one CZ505 Gibbs I've played with fed TERRIBLY with woodleigh softs. I didn't even look at their mag box. The single stack is the answer. One of these days I'm going to machine up a bunch of SS Boxes and offer them for sale.-Rob

Robgunbuilder,
HA!/DOA would like to try out your SS Box for the CZ .505 Gibbs whenever they become available.

OK, but this needs the right follower to make it work. Also, I don't think anyone, even a retiree can justify the time it would require to machine one of these one-off when you can buy one for about $300.

Width at front, .870
Back, 1.089
Length, 3.95

These were taken with my plastic-fantastic RCBS dial caliper so take it with a grain a of salt.

tiggertate,
That is interesting.
By the Mauser-cosine/rubber-band-and-measure-a-bundle-of-three-cartridges method, the rear width of the box inside should be about 1.185" plus a few thou for tolerances, maybe 1.190" would be a comfortable fit?

If yours is 1.089" that is 0.1" too narrow.

A compromise there too, but I guess it works.

A Rigby/Lapua box ought to be about 1.090" at the rear.

jeffe,
The only thing special about the CZ 550 Magnum box in the .505 Gibbs is, well, nothing.

It does come with a very thin magazine follower, and that allows the three Gibbs cases to fit comfortably in the standard box.

BTW, the standard CZ 550 Magnum and forerunner BRNO ZKK 602 boxes are very close in size to the Blackburn .505 Gibbs box that tiggertate has:

The box on my .500A2/.510JAB that will be converted to .510 Gibbs-Bibi measures inside the box:

3.850" long (just right)
1.050" width at rear (only 0.039" smaller than Blackburn)
0.858" width at front (only 0.012" smaller than Blackburn)

As tiggertate pointed out, a special follower will be required for the .510 Gibbs-Bidi.

That will make it a shop mule limping along until a vertical-stack-single-stack/in-line magazine can be had.

I have a suspicion that the ancient ones building those rare original Gibbs .505's, numbering only 35 produced, were probably using the wrong box dimensions too.

I do wish that sumbuddy who know will prove me wrong.

Who's got one of those 35 original .505 Gibbs to measure the box?

How about a Ryan Breeding .505 Gibbs box dimensions, eh? Hmmm? What?

Ron,

Go to NiroExpress

http://forums.nitroexpress.com/ubbthreads.php?Cat=

One of the Australian posters who I think goes by 500Nitro has an original 505 Gibbs.

Mike

When I finally corectly fixed my .500AHR on the CZ550, I used the rubber band/cosine rule trick and made a sheet metal box exactly .030 larger than the stack dimensions all the way around. The box was tig welded together in the front as I recall. I reinforced the front of the mag with some .100 sheet metal that I spot Tig welded in place. This keeps the bullets from banging the box out of shape.
Now for the fun part. I assembled the whole box and scribed the outside of the box onto the inside of the CZ action ( hint use Dyechem) then I milled out the action to those exact dimensions. Being carefull to depth the new inner lip the same as CZ used. There was precious little metal left. I was able to use the CZ follower with just a little more milling to fit those fat .500 AHR's. What your looking for is each cartridge sliding smoothly up the box into the action and lying parralel against the right or left action rails. Now this cartridge is rebated so feeding seems to be inherently more difficult to achieve than with non-rebated cartridges. However this is at least the process I used. End of feeding problem.-Rob

i wonder how fast a 505 gibbs can push a "b.b."

hmmmmm....lets see a 5 grain bullet does anyone know the diameter of a b.b.?

i'll guess it will push it out at 7,000fps providing there is not an explosion

Mike378,
Maybe one of these days I'll go troll that site to beg the "Original .505 Gibbs" owner to divulge the inside width of the rear of the box. Thanks.

Robgunbuilder,
I and a mechanical engineer-gunsmith here at HA!/DOA will be developing our own properly sized and reinforced box and follower for the .510 Bibi. Thanks for the pointers.
Then we will fix the CZ Safari Classic .505 Gibbs box. Shameful of CZ to do it that way. All they really did was put a thinner follower in it.

Post Script: the .510 Bibi is now become the .510 Ndovu. Name change. Dead serious.

Hello..lemme preface by saying I am way out of my depth here, but I do have a question. I really like the look of the .458 Lapua-Tembo. The first question I have is where can I get more info on this cartridge?
Secondly, as I understand it, this is a necked up 338 Lapua. Now the 338 Lapua is a necked down 416 Rigby according to Lapua. There doesn't seem to be too much of a shoulder on the 416 Rigby and yet there is a shoulder on the 458 Lapua Tembo.. I ain't a smart man but I would sure like to know a little more. I'll do the reading if somebody can light the way.

the lapua and rigby cases are SIMILAR but not the same

quote:

Originally posted by Tombo:
Hello..lemme preface by saying I am way out of my depth here, but I do have a question. I really like the look of the .458 Lapua-Tembo. The first question I have is where can I get more info on this cartridge?
Secondly, as I understand it, this is a necked up 338 Lapua. Now the 338 Lapua is a necked down 416 Rigby according to Lapua. There doesn't seem to be too much of a shoulder on the 416 Rigby and yet there is a shoulder on the 458 Lapua Tembo.. I ain't a smart man but I would sure like to know a little more. I'll do the reading if somebody can light the way.

Like boom stick says similar but not the same.
The 338 Lapua was developed for a military sniper cartridge. They tried the 416 Rigby case and found it too soft (it was not up to the pressure required). So they made there own, similar dimensions but shorter in length and much stronger.

rip has one...it does 2500 fps with 500 grainers but 2300 is all you need

we have also come up with the "short" version that will fit in a win mag but the rifle has not been done yet.

check this out...

https://forums.accuratereloading.com/eve/forums/a/tpc/f/4711043/m/222107693



458 "boom stick"
458 tembo short nose
458 tembo long nose

boom stick,
You have to get the Lapua shoulder angle corrected to 20 degrees! Not 25 and change!

The Lapua and Rigby cases are externally identical up to where the Lapua shoulder starts.

Any difference in the base is merely a matter of the max and min dimensions on the head and rim: 0.588" to 0.590"

The Lapua is stouter stuff than the older Rigby stuff, ja!

quote:

Originally posted by Tombo:
Hello..lemme preface by saying I am way out of my depth here, but I do have a question. I really like the look of the .458 Lapua-Tembo. The first question I have is where can I get more info on this cartridge?
Secondly, as I understand it, this is a necked up 338 Lapua. Now the 338 Lapua is a necked down 416 Rigby according to Lapua. There doesn't seem to be too much of a shoulder on the 416 Rigby and yet there is a shoulder on the 458 Lapua Tembo.. I ain't a smart man but I would sure like to know a little more. I'll do the reading if somebody can light the way.

Tombo,
You are obviously an intelligent man with good taste in cartridges. The .458 Lapua Tembo is indeed faultless, with plenty of shoulder, plenty of taper, slick 20 degree shoulder angle for semi-auto fire, plenty of neck, no rebated rim, perfect case capacity for 2500 fps (or less) with 500 grainers.

What more could anyone want?

Since the Tembo shoulder is a little closer to the base than the Rigby's, the shoulder diameter is a little wider there.

quote:

Originally posted by boom stick:
the lapua and rigby cases are SIMILAR but not the same

The 25 degree 67 minute shoulder angle is really a hoot! That would be 26 degrees and 7 minutes if it were correct. It is not.

The .338 Lapua and .416 Rigby cases are identical externally up to where the Lapua shoulder starts. Any differences in the case heads are internal.

Varying specs of even 0.585" to 0.590" on the rim and base are merely max and min or real world measurements of functional brass.

Anything bigger than 0.590" would be a no-go in either .338 Lapua Magnum or .416 Rigby.

This 338 Lapua vs 416 Rigby cartridge case brouhaha reminds me of Layne Simpson trying to explain to me at a SHOT Show how his 7mmSTW was not a 40-year late(r) twin (blatant copy?) of Mashburn's 7mm magnum wildcat from the WWII era. "...'cause Mine is based on the 8mm Rem Mag case not a blown-out sharp-shouldered 375 H&H...". How old is the 416 Rigby? How old is the 338 Lapua? This brawl has all the importance, aside from somebody's ego needing stroking "ME! ME! Mommy, ME! was first!" of a forum is very interesting, but 785 posts touting the superiority of a 535gr bulet versus a puny 530gr version is a bit childish. You guys need to get a real life, even if you have to lease it.
Shoot 500 Cape Buffalo with each and show me the field autopsy reports if you can find any discernable difference.

regards,

the man from U.N.C.L.E.

wow...you realy are new here...

most here just LIKE arguing...its a shooters pastime...

what is your life like that is so superior to any of ours?

happy hunting and straight shoot'n

maybe a better name for you would be sharps-shooter...

the diffs between the lapua case and the rigby might not seem evedent on first glance but the rigby requires a BIG action usualy costing buco bucks compared to the lapua...

the lapua case is stronger by design


the lapua brass is cheaper


the lapua comes in 30 and 338 cal but can be necked up easily compared to necking down (harder)


more rifles are chambered in 338 lapua than rigby


ect ect


please post pics of your buffs

All that meat.Yum Yum!