Check these sites out

http://www.470mbogo.com/

http://www.470mbogo.com/Page5.html#

Great stuff and a good read.

Mike

Thanks Mike! I enjoyed it. Glad you're feelin' O.K. again Mate. Welcome back.

Nick

Mike 375,

That chap domesticated and gave a pet name to the wildcat Saeed worked up in the reloading data section: Saeed's .475/.416 Rigby Improved is the .470 Mbogo. I read this webpage a while back from one of Dane Burns posts maybe? Anyway, it is a good read and shows a lot of enthusiasm and good info for aspiring wildcatters of big bores.

Nickudu,

I haven't totally abandoned the .510 BS, but how about some other wildcat ideas:

.375/.338 Lapua
.416/.338 Lapua

The Lapua brass has got to be some of the best in the world and available at only $2 a case. This could be the "Rigby Improved Pondoro" line or whatever. The .375 RIP and .416 RIP? Just some more BS.

------------------
Good huntin' and shootin',
Bwanawannabe, Daktari Ron

"RIP" = "Rest In Peace" = Yes!

I'm hung up mentally on the .50's lately Doc. Can't think of anything else. I think your .510 JAB case is one of the best balanced for my idea of a usable, everyday,.50. I think we both like the "AHR" case also? Thing is I'd probably wind up with the 600 grainers @ 2300 or so, anyway, so I might as well just stay pat. Last time out, I put 6 in 1.5" @ 100 yards with the 600 grain solids and 6 in 2.25" with the 570 grain "X". All are doing 2320 to 2330 fps. with the 120 grain, RL-15 load. I assume I can equal this velocity with either the .510 JAB or the .510 AHR but at what pressure?
I wanted .50 caliber bullets with decent sectional density numbers, good hunting velocities and moderate pressures.
I'm sitting pretty right now dude and feeling nearly as dangerous as Zero Drift!

[QUOTE]Originally posted by R. A. Berry:
[b]Mike 375,

Nickudu,
I think that you'll find the 470 Mbogo cartridge that I desingned presents a real problem if you try to form it from factory 416 Rigby brass. The Mbogo brass has a length of 2.9450 to the case mouth and the 416 Rigby measures 2.900. That is why I started with the 416 Rigby cylindrical brass from Mast Technologies. There was a Doctor that I spoke with that was using a 475/416 wildcat but I wanted the largest possible case volume in order to keep the pressures down. I've never tried to form the brass from a 416 Rigby brass but I'm now going to give it a try. I think the brass will end up with a very short neck. I'll let you know how it turns out. Where are the loading references that you refer to when you mention the cartridge that Saeed worked up? Did you enjoy "Comparing the Big Bores". Very impressed to see that George Hoffman writes here. Loved his book "A Country Boy in Africa" Picked it up at Holland and Holland on the stop over in England. 470 Mbogo

[This message has been edited by 470 Mbogo (edited 04-16-2001).]

470 Mbogo

http://www.accuratereloading.com/

That link tales you to the open page for this site.

The opening picture is Saeeds reloading room.

Scroll down and you will see Reloading Pages.

Mike

470 Mbogo,
I read you story about your .470, it sounds like a real thumpber...I also, noticed that you were hunting around some of my old hunting areas. We use to cross the Kilombero on the ferry at Ifakara, then just across the river at the first villiage turn left and go either into the Selous on just on it's boarder. A lot of buffalo in there after the grass is burned. I wish you great success with the 470 wildcat.
George.

[QUOTE]Originally posted by George Hoffman:
[B]470 Mbogo,
It's really nice to hear from you Mr. Hoffman. The area that we hunted in definitely has a lot of Buffalo and I remember you mentioning it in your book. The part I liked was no motorized vehicles. All travel in the upper camp area was by dug out canoe. I took my 470 there in September of 98 and I'm hoping to return in 2003. The 470 Mbogo project started in Oct. 97 with JGS reamers. The idea started with my Ruger 77 Mk 11 in 416 Rigby feeling very barrel heavy in July 97. It took a little while to figure out what to do and how to go about it. It was because of the fine writers and good articles available that a person was able to source names products and ideas to make a personal project come full circle. It's been a very good experience. The computer part is all new to me but I'm catching on. Will you be writing any new books?

The results of "Comparing the Big Bores" are the same as at www.grosswidjagd.de , chapter on penetration. Nearly the same ranking and numbers with the exception of .416 Rigby. The 4x4 tube test may give some more weighing for the energy. I did not understand it fully. Is the displacement of that sand filled tube measured? What are the shooting distance?

In general it shows again the overrating of some of the old Big Boomers.

------------------

Mr. Hoffman,
Would you kindly email me as to acquiring a copy of your book? I am anxious to read it.

470Mbogo,
Welcome aboard! I was most impressed with your shooting / reloading video.
You can be my "back-up" anytime!!

[This message has been edited by Nickudu (edited 04-16-2001).]

[QUOTE]Originally posted by Norbert:
[B]The results of "Comparing the Big Bores"

The 4x4 square tube test is an impact comparrison. The tube weighs 35lbs which is fixed. The harder you hit it the further it will travel. The distances measured and posted in the tables are the result of travel for each cartridge. They are all shot point blank. Click on the picture and it will give you a description and will make it all clear. There is a fair amount of text explaining each test. 470 Mbogo

470 Mbogo:

That may have been me that made the comments you were attributing to Nickudu.

I recall now how I found your website. It was mentioned somewhere in the SCI newsletter. I believe I printed out most of the text and data and filed it away for future reference, as I have done with Saeed's load data. I will have to go back and look at the comparison of big bores testing to make any further comments.

------------------
Good huntin' and shootin',
Bwanawannabe, Daktari Ron

Nickudu,

Why mess with success. Your fifty is as good as any fifty and better than most.

I am partial to the .510 JAB, for selfish reasons, and practical reasons. I think my pressures are below 50,000 PSI. I don't have the pressure testing capability. Check out the pressure data for the .500 A-Square in Art Alphins manual and you will see how low they are supposed to be by him.

Also if you want to say it in Latin, "RIP" is "Requiescat In Pacem." "Rigby Improved Pondoro" has a better ring to it, IMHO, but the double entendre always keeps 'em guessing if one is in the BS line of hobby like me.

------------------
Good huntin' and shootin',
Bwanawannabe, Daktari Ron

[This message has been edited by R. A. Berry (edited 04-17-2001).]

Bwana Daktari,
You know there will always be the "next project". The Lapua brass R.I.P.'s sound like fun but somewhat redundant, No?
A .580 R.I.P. (or "BS"), launching the 750 grainers at usable hunting velocities should be the next focus, IMHO.
The Tyrannosaur and Nyati cases are overly large and fraught with design flaws for bolt action application. We need to determine our desired velocity and come up with the right case.
The "Bwana Saeed Index" indicates that 2200 fps would be no less effective than maximum T-Rex loadings approaching 2500 fps. At this velocity the .580 would, however, still be a good bit more powerful than the standard .577 while providing increased shootability in the field. Housed within a properly made 12 pound rifle, this could prove to be a viable super heavy for Ele and Buff.
How'bout a blown out Gibbs case (haven't looked yet, just "BS"ing here)? Would there be enough shoulder to work with? At 180+ grains of water, it may do.

[This message has been edited by Nickudu (edited 04-17-2001).]

[This message has been edited by Nickudu (edited 04-18-2001).]

For cases you may want to look at what they are cooking up for the .408 Chey-Tac. They brass is based off of an improved .505 Gibbs in much the same manner that the .338 Lapua was originally based off of .416 basic brass.

They idea behind the .408 is an improved medium tactical cartridge for hard target interdiction, ie putting a hole in a rocket booster renders it useless.

The point for sporting use is that a new case designed for higher operating pressures of high quality fabrication would lend itself readily to wildcatting and perhaps be better suited than the original .505.

As it exists in it's current loadings, using Lost River Ballistics projectiles, the round is projected to stay supersonic to 1800 yards. I would imagine that with an appropriate hunting bullet, performance ought to be interesting.

Yes that is, indeed, interesting Rust.
The .408 CHEY-TAC... Have you any idea where I can get more details about the case?

Thanks Much!

hey mbogo,

Did any of those solids break apart or bend at high velocity?

[QUOTE]Originally posted by 500grains:
[B]hey mbogo,

500 grains,
All the solids were in perfect shape and my son will be putting them up on the site as soon as I can get back to Vancouver with them.He will also be putting up the video that I measured the recoil numbers from.The thing that impressed me was the shape that the solids came out in after the square tube test. With all the shots at point blank range I'm sure the majority of the shots still hit the end of the steel tube. The sand would definitly slow the velocity down rapidly and the energy would be used up with the movement of the tube at the same time. It seemed the biggest amount of damage was done when one solid would come in contact with one of the solids already in the tube. The majority of these solids were still in pretty good shape. Nickudu have you designed your own .510 cartridge? How about some information? I tried fire forming some 416 Rigby brass in my 470 but as thought the neck only measured .310. The Mbogo case is 2.480 to the shoulder which measures .5750 and then has a 35 degree shoulder and a .400 neck for an overall length of 2.9450. Does anyone know how Dane Burns has made out with his .505 wildcat?

470Mbogo,

"Comparing the Big Bores" gives valuable results and discussions. But the figures for the .416 Rigby are not consistent with experiences from the real world. Since Taylor�s report it is one of the most effective and penetrating big game cartridges.

Some remarks on the experimental setup:
Penetration test: It is not advisable to perform such tests with only a few inches distance from the muzzle to the target. The bullet is not yet stabilized and its yaw can cause tumbling and some irregular effects. The Greenhill formula for twist stabilisation seems not to be sufficient for the bigger bores as observations in practice show. That may be the reason for what happens with the soaked paper tests. Also recent reports on bending or disintegration of solids are performed at too a close distance. If a solid tumbles and travels sideways, it can not withstand the enormous forces acting on its shank. It is simply constructed for straight travel through the target. When I shot penetration tests at 100 yards I never had deformed or broken bullets nor was it possible to produce an irregular path of the bullet in the target. (Even with soaked paper or angeled plywood or other tricks).
Sand filled tube: A sand filled box on a pendulum was in former days used to calculate the velocity of a bullet using Newton�s law of conservation of the momentum. The meaning of a sliding box is not so clear, because the differences from easily to calculate figures
are caused by different energy dissipation (in the sand and on the sliding surface) into heat during bullet impact. What does it mean "to hit harder"? We are not going to throw back an animal by the momentum, but to destroy its vitals.

------------------

Norbert- I agree with your point of conducting penetration tests at some distance. It goes hand in hand with allowing bullets to "go to sleep" while checking your 200 yard targets rather than only 100 yard targets. As has happened many times, the bullets that shoot the larger groups at 100 yards sometimes shoot the tighter groups at 200 and out. It simply demonstrates they needed a bit of time to stabilize.

470Mbogo - Bwana Daktari Ron and I often "BS"
about various big bore cartridge scenarios.
We enjoy doing so. He has designed the .510 JAB cartridge and introduced the "Bwana Saeed Index" to be found in our "FAQ" area. Recently, we have been talking a lot about creating a line of cartridges with the "Bwana
Saeed" name tag. This most recent one, concerning an improved Gibbs case to house a .577 bullet is something I plan to look at more closely. The goal is NOT maximum velocity but maximum utilty for a .577 caliber / 750 grain bulletin a bolt action rifle. In other words, an efficient, more easily adapted case, providing realistic and usable performance at acceptable pressures.

Nick, here is a little information on the .408. First off is an article dealing with the development of the cartridge.

http://www.snipersparadise.com/ELR/CheyTac.htm

Second is a copy of a posting by one of the guys working on the development. While it might seem to be from sort of an off beat forum, someone is always cooking in the kitchen with Dinah so to speak. New developements from respected names don't come along that often.

"The case is based off of the .505 Gibbs case. It has a .635 case head size and the case is 3.25" long. OAL with the 419 gr. bullet is 4.515"

The 419 gr. bullet is a CNC lathe turned copper / nickel bullet. The projected BC off of the PRODAS program is .900. Our range testing next week will give solid BC data back for ranges to 2700 yards or more. We will be shooting the gun to supersonic max range and into the sub-sonic range.

The rifle is currently built by EDM arms and it is a scaled down .50 Windrunner. The size of the cartridge dictates a larger than standard magnum length action. The McBros Talon, Dakota Safari, and Hall Express ( I think ) will handle the cartridge. We are also doing a 305 gr. bullet for a certain tactical application.

Upon approval from the design owner, Dr. John Taylor and completion of next weeks work, I will be able to release a sensitivity analysis of the .408 vs .338 Lapua and .50 BMG using military and AMAX loads. I have the predicted data right now and won't release it until it's proven data."

This will pretty much eliminate blind load developement too, which is a bane to me. I always prefer to start with data from some reliable source.

Thank you Rust. I do recall a certain magazine article, now that you have jolted my memory. Well it looks as though they have reduced the Gibbs case capacity by 20 grains of water but it still looks like one nice case. Maybe not for .585 bullets but for the
.510's it holds more powder than the A-Square.
I'm gonna draw it up and study it some.

Thanks Once More

[QUOTE]Originally posted by Norbert:

Norbert,
If you mean John Pondoro Taylor when you mention Taylors report, think of the date the book was written and the cartridges that were available to compare to. He mentions the fact that he thought the Rigby was such a killer because of the great solid bullet design. They would never fail or break up. He never had a 450 Ackley or a 460 Weatherby that could shoot bullets at 2400 fps with a sectional density of .341 Check the sectional densities of the bullets compared. The higher the sectional density the better the penetration all else being equal. Lower sectional density with higher velocity improves penetration. There is no doubt that the 416 caliber bullet is a great penetrator. Also keep in mind that the bullets were Barnes solids not the Hornady style bullet shape. I mentioned that it was important to keep this in mind when looking at the tables. Did you notice that when I loaded three different shaped solids at the same velocity with my 470 Mbogo that there was eighteen inches difference in the penetration? As far as close up shots all bullets travelled in a straight line and there was no yawing or tumbling.All of the bullets were recovered in perfect shape.Remember with the setup I was able to monitor the bullet travel every 3/4 of an inch. The only time I've read about the problem you're mentioning is when the test rifle had a real slow twist rate. We don't have that problem. How big of a test box do you think you would require in order to shoot eleven shots into it at 100 yds. and have no interferance between bullets passing through? Keep in mind only one rifle has a scope and some rifles are loaded to two bullet weights and four velocities. Up close so you can square the rifle vertically and horizontally is the only way I could figure.
Only field artillery will throw back an animal by momentum. It's like baseball the ball is the fixed item you hit it harder it goes further.Lets call it a hitting comparison. I think the problem with the wet paper is the voids that can be created and the bullet going for the path of least resistance. When pulled a certain amount all hell brakes loose.Remember the paper was packed as tightly as possible into the same box used for the plywood test box so that we would be able to measure distances easier. If it was packed into cardboard boxes it might have turned out better. I'm trying to get hold of some of the paper from the local pulp mill. It measures 3 ft. by 3ft and is consistent so I'll try again when the pile hits 5 feet. Also with the square tube test keep in mind that all of the bullets energy is used up in the tube and it is the same for all the bullets tested. 470 Mbogo

470 Mbogo,
I agree that Norbert has some valid points to consider. It is constructive criticism that is offered to clarify our thinking. Norbert may come across as a bit "testy," but it is really only in a rigorous critique mode of the scientific thinker. Any such exchange can enhance our understanding.

So... I read your comparison testing of the big bores. I liked it greatly. One tiny typo is the sectional density of the .510 caliber 600 grain bullet: it is 0.330 not 0.336, which is the s.d. of the .505 caliber 600 grain bullet.

It is interesting that your 4x4 Square Tube Test seems to correlate very well with the BSI rankings of the Bwana Saeed Index, though not with linear correspondence, but in a valid manner. This may be a good objective measure of "whomp" which the BSI purports to measure. I like it.

I did note a small flaw in your using .510 caliber bullets to simulate the .505 caliber bullets of a classic .505 Gibbs load. Forgivable, however.

There was a little homecooking in switching to the Woodleigh solids in the 470 Mbogo and then mixing that orange in with the rest of the apples on the penetration and 4x4 tests, but at least you pointed that out. It is interesting that the Woodleighs did better than the Barnes solids.

All in all a good piece of work and a pretty good chore to pull off. Thanks for the enlightenment.

BTW, if you are interested, my .510 JAB is the .510/.460 Weatherby Improved Jenkins And Berry. It is a modified .500 A-Square with a slightly different shoulder angle and slightly different neck length and a throat of either 0.300" or 0.588" freebore instead of the .500 A-Square nominal 0.400", depending on whether one wants to shoot the 750 grain Hornady A-Max for accuracy at 1000 yards or 570 to 600 grain hunting bullets at 50 yards. I have a Ruger No. 1 with the 0.588" throat and 27" barrel, and a BRNO ZKK 602 with the 0.300" throat and a 23" barrel. It is a hoot.

------------------
Good huntin' and shootin',
Bwanawannabe, Daktari Ron

Bwana Nick,
That was some pretty good BS you pulled off there. I am afraid the .505 Gibbs case is too small to make an adequate shoulder for the .580 wildcat. The Nyati with its 0.660"(?) diameter is marginal as Ross himself will admit. The T. rex case (bigger still) or Nyati case would have to be used.

BTW, I think I am going to meet Mitch at the rifle range on Long Island this Saturday if all works out to see if he will let me fire his dinosaur rifle as part of R&D for my master plan of rifle building. If I survive, I will report back here. LOL. Requiescat in pacem.

------------------
Good huntin' and shootin',
Bwanawannabe, Daktari Ron

Be careful with that fellow Mitch, Bwana Daktari. I hear he has a sneaky button-operated shroud that seals off the muzzle break on guys who want to shoot his T-Rex!

Gentlemen,
I see some of the penetration test done here by different fellows are suggesting that the tests be run at a 100 yards. May I suggest that this is not the real world either. If you intend to realy test a solid, why not at ranges from 15 to 25 yards. This is the distance that a real life charge would be encountered. I have always conducted my tests at the 15 yard distance. You will gain some deeper penetration by raising the veloicty. i.e. a 416 at 2400 fps will be 2-3 inches less than the rigby loaded to 2600 fps. But I do not think you will gain or need any more on game. I still use 3/4" plywood cut into 12x12" squares and stacked like a loaf of bread . In this medium I can usually get 40 to 41" of penetration from a 410gr Hornady bullet and 30 to 31 " from an monolithic type solid. Using wet paper causes seveal problems. One, depending on how tightly the bundles is bound makes a difference in how well the water penetrates the paper. Phone books or yelloow pages are very cheap paper and readily asorb water bettter than a hard slick finished magazine.
when shooting into wet paper the bullet pushes a wad of paper ahead until it gets built up enough to go to the side, this can in turn cause the bullet ot turn and diviate and come completely out of the medium. Finn AAgard and I dicussed this several times.
You will never have this with plywood, and can repeat a comparision test a year later and still valid. Due you inconsistentices
with the paper method I think it could only be valid for that number of shots used at that time. There are probably better test media out there, but a poor boy con only do so much with limited funds. But it is fun.
Keep yp the good work every one, I like it.
George

George,

Have you ever done penetration tests on plain old water? I know it doesn't perfectly correlate to muscle in bone, no media does, but it seems like a good medium for relative penetration. My thought is to set up a trough and use multiple gallon ziplock bags full of water. Relatively cheap, and very repeatable.

Georg,
I performed penetration test at 20, 50 and 100 yards. I mentioned the 100 yards tests because they gave the most consistent results comparing different calibers. I think our big bores are going "asleep" at about 20 yards. I also made penetration tests on fresh ele bull heads at 20 yards to determine the behaviour at all possible angles. That�s obviously testing in the real world!
470Mbogo,
independent of what Taylor said, the .416 Rigby is a great penetrator and elephant killer, only a little outperformed by the .458 Lott and Ackley and some .470 and .500. The sectional density of the original 410 gr bullet is .338, not too much different from the .341 of the 500 gr in .458 caliber.
What you said about penetration, SD and momentum is the same as I said. I am always afraid, that my limited english is not good enough to explain my thoughts clear.
There is one thing controversial and should be more clarified: You observed, that three different bullets showed relevant differences in penetration. I guess that it is not caused by the different shape of the nose but by different yaw in the target at those short distance. It is difficult to check this from the bullet path in the plywood. I observed in a similar experiment in a special material different diameters of the holes on the bullet path. That means different energy loss and different penetraion. Haley published recently in the African Hunter similar tests and observed identical penetration for three different .458 bullets (Monolithis and FMJ). That in your tests the Hornady shows more penetration than the monolithics is an indication for more stabilisation and less yaw in the target, because it is the shortest bullet used.

BTW. square tube: Not all the energy is used up in the tube. The sliding tube is acting like a brake and uses up also a fraction of the energy. The question is: how much. But not so important.

For the hunter I always have the advice:
Use a big bore bullet with a SD greater than .33 and a velocity around 2300 / 2400 and you have a real performer.

------------------

[This message has been edited by Norbert (edited 04-19-2001).]

[This message has been edited by Norbert (edited 04-20-2001).]

[QUOTE]Originally posted by George Hoffman:

George
Are you still working as a PH and if so what areas do you work? The 416 caliber cartridges are great penetrators. That is one reason that at the end of my article I mentioned to keep things in perspective that all the big bore rifles tested are more than capable of taking any game on earth. I have two 416's, one a Taylor the other a Rigby. I've shot two very big bodied Moose with my Taylor on our annual trip to Northern B.C. The first bull was a thirty yard shot with a 350 grain Barnes X bullet. It was a straight on chest shot that was recovered at the hind quarters with the bullet recovered in perfect shape. The other was on a day that was crystal clear and fifteen below. I had a 400 grain Hornady soft point and a straight on shot at the chest. Being dressed for the weather and still packing my back pack I shouldered the gun against the heavy strap and managed to pull the shot and hit the Moose through the front right shoulder. The bullet penetrated and cut the entire shoulder blade in half as if it was cut with a band saw. Some how the Moose made it back up and I was able to hit it broadside. At fifteen below with a fist size exit hole it was steam from two sides and over. The 416 may be overkill (pardoning the expression) for Moose but we do get harrassed by our politically closed Grizzly Bears. In the thick willows it's handy. Having bears in your camp at night is quite common in the area we go to. Hang those quarters high. Did Nick get a copy of your book? I know I sure enjoyed it. You've had a wonderfull life style with your wife. Good on you. If you are still hunting in Africa send me an e-mail with some info. dave_estergaard@sunshine.net A quick side note on how difficult it can be to put together a project like Comparing the Big Bores. I called Barnes to order the different solids I would need and everything was in stock. With the paper work almost completed I was giving my address for shipping. When I said Sechelt B.C. Canada it came to a halt. I'm sorry sir Barnes doesn't ship to Canada. Beauty! 470 Mbogo

470 Mbogo,
Thank you for the questions. I have not been to Africa since "99" The place where I was taking clients in Zimbabwe his concession was taken by a local political conected "person" . I think he has got in back now or at least he can take some clients there, because the "person" could not get any clients. My biggest problem right now is I have Prostrate cancer, I am making arrangements just now to go to Alanta GA and have an implant and six weeks of radations. I have two friends that have had this procedure with very good results. I think you can get about 10 more years this way. Now, back to africa, I have been contacted about going back to Tanzania, in the future. However, I want to get all of this other behind me, then I won't have to many worries. I should know something late this summer, but If I do go, it will be in the 2002 season. Thanks again..
George

[This message has been edited by George Hoffman (edited 04-21-2001).]

[QUOTE]Originally posted by George Hoffman:
George,
Sorry to hear about your situation. Hope all goes well for you and that your in Tanzania for 2002. Best Regards 470 Mbogo

[QUOTE]Originally posted by Norbert:
Norbert,
You comments on the fact of the shorter bullets penetration being deeper than the long for caliber Barnes solids could be right on the money. But there deffinately is a big difference. Most of the rifles used had a 1 in 12 twist and that should be lots to stabalize any of the bullets used. That's one of the nice things about the .475 caliber bullets is that a 500 grain .475 is considerably shorter than the same weight .458. In the 470 Mbogo case with the bullet seated to the OAL of 3.750 inches the bullet base is even with the bottom of the case neck. With a .458 the bullet seats well into the powder area of the case. I would really like to see a 535 grain .475 bullet. It would really have a great sectional density and still wouldn't be overly long. I once wrote to Steve Hornady to ask if he was considering manufacturing a 500 grain .475 soft point and solid. His reply was I won't say yes and I won't say no. I've measured some .475 bullets that are as small as .4725. To load these you have to resize them to remove the old primer and then take the expander ball off and size them again. This will give a good neck hold. The other thing with penetration, especially solids, is that you can see from many of the videos out that many of the guys shooting 470 Nitro Express doubles get complete penetration as you can see the bullet hit on the far side regularly. Many of the big bores are capable of full length penetration on Buffalo.One bull I shot straight on with a 500 grain Swift A-Frame penetrated straight through to the hind quarters and mushroomed out to .879.
The damage was devestating. That's one big hole. I'm sure a solid at .475 would have left that Buffalo 470 Mbogo

470 Mbogo,

In your tests for the 450 Ackley, were the Hornady bullets the new or old style?

-redleg

[QUOTE]Originally posted by redleg155:

Redleg,
I would have to think that they would be the old style because I can't find any information on any new style. They were the standard .458 Solid that Hornady put out over the last ten years. Would apreciate any info on new Hornady bullets. Did they come up with a couple of new .475"s?

[QUOTE]Originally posted by 470 Mbogo:

Redleg,
The pictures of the recovered solids from the plywood penetration test are up on the site now. Make sure you click on the picture for the description etc. The correct sectional density for the .510-600 grain bullet is posted also. Interesting that the .416 at the beging of the list and the .510-600 grain at the end of the list have the same sectional density and when driven at the same velocity of 2400 fps that the penetration was within an inch and a half of each other. Mind you one is making a lot bigger hole but interesting.

470Mbogo,
only a short addendum:
A bullet leaving the muzzle is never stabilized, independent from the twist rate. That means, it shows condiderable angle of yaw. The twist determines, at what distance the bullet becomes "asleep", or is travelling straight. This happens yards from the muzzle. Experimental results on modern military rounds gave figures up to 90 yards. Our big bores are stabilized earlier. My impression is at about 20 yards. If overstabilized (too much twist), the bullets nose is not following the bullets path and we have again an angle, but not yawing.

------------------

470Mbogo,
only a short addendum:
A bullet leaving the muzzle is never stabilized, independent from the twist rate. That means, it shows considerable angle of yaw. The twist determines, at what distance the bullet becomes "asleep", or is travelling straight. This happens yards from the muzzle. Experimental results on modern military rounds gave figures up to 90 yards. Our big bores are stabilized earlier. My impression is at about 20 yards. If overstabilized (too much twist), the bullets nose is not following the bullets path and we have again an angle, but not yawing.

[This message has been edited by Norbert (edited 04-22-2001).]

[QUOTE]Originally posted by Norbert:
Norbert,

O.K. you've got me on another project. I'm away for 8 or 9 days but as soon as I get back it's off to the building supplies for plywood. I'm going to load up some more 416 Rigby rounds and shoot the 12 by 12 plywood squares at point blank, 25 yds., 50 yds. and 100 yds. I'm curious as to the difference in penetration. I'll post the info when I get a chance to do it. The plywood will be sandwhiched the same way George was describing because I've already dismantled my plywood box. I've worked out the different starting velocities in order to have 2400 fps at the point of impact. they are as follows: 2400 fps @ point blank, 2460 fps @25 yds, 2515 fps @ 50 yds. and 2635 fps @ 100 yds.

[This message has been edited by 470 Mbogo (edited 04-23-2001).]

470Mbogo,
good news. I would like to learn more about the different bullet styles and nose shapes. Try to get as many as you can.

------------------