Posting for Dr Mauritz Coetzee:

THE EDITOR
ACCURATELOADING.COM


Dear Sir

I refer to Mr Koos Geldenhuys and his communication with Chris Bekker regarding myself.

Due to hunting and work commitments I have been unable to reply to Mr Koos Geldenhuys' rather emotional allegations.

Before I start, the following brief background to my communication with Mr Koos Geldenhuys.

I wrote an article on the 375 H & H cartridge in a South African magazine. In this article I mentioned that the 380/375 Rhino bullet with an expanded diameter (an average) between 24/25 mm creates a massive wound channel and enough penetration due to its high sectional density.

I received an e-mail from Mr Koos Geldenhuys stating that sectional density is a myth. His main argument was that due to the high expansion rate and diameter of this bullet, momentum will be greatly compromised with a resultant bad penetration and wound channel forming.

I consequently supplied him with practical field results and the names of professional hunters who have used this bullet with great effect. Everybody involved with the actual field results agreed that the bullet provided more than enough penetration and impressive wound channels.

In his response Mr Koos Geldenhuys accused me of not explaining the value of sectional density in the performance of the 380/375 Rhino bullet. He also stated that he was not interested in field results but rather in concrete facts.

My answer with regard the sectional density question was rather simple: the bullet, on average, shows a high weight retention factor. Although the sectional density is lowered quite drastically, the high weight retention factor contributes to its momentum.

What I did find rather astonishing at that stage was his remark with regard to hunting experiences and so-called concrete facts. What could be more concrete, fact wise, than hunting experiences?

I also asked Mr Koos Geldenhuys whether he has any model or theory, with a real-life or empirical foundation, which can predict as to what constitutes too much momentum reduction and also as to what constitutes acceptable momentum reduction (and penetration).

I never received a reply from him on this question. Because of this I am quite amazed about his stating that I was unable to follow the links he supplied. His assumptions about over expansion, shallow penetration and consequent bad wound channel forming were all tied up in one problem area, namely how come the bullet performs so well especially on buffalo.

I even supplied him with the cellphone number of Oela Heineman, a well-known professional hunter. Oela, using the 380/375, shot lengthwise through the body of a charging lion. Jacques Hartzenberg, of Chupunga Safaris, also used this bullet with great success on lion. Video footage is also available on these hunts.

I also mentioned the experiences of Kevin Robertson, (Doctari) author of the book "The Perfect Shot", to Mr Koos Geldenhuys. In this regard, I refer to an article which Kevin wrote in "Accurate Rifle" (March 2004, Vol 7 No 2);

"… subsequent experiences has convinced me that these super heavyweight bullets are capable of elevating the already good .375 H & H to new previously unthought of heights.

In fact, I believe these bullets effectively shift the .375 H & H up a gear and into the next calibre class – the 400! I did manage to get my client to use his expanding 380 grains to take six buffalo during the 2002 hunting season. When pushed to about 2200 feet per second, they performed most impressively, and as it was my impression that the usual impact of them hitting buffalo was similar to that which occurs when one of the 416's is used. All but one of the bulls shot were one-shot kills and I was able to recover most of the Rhino's…"

This man has done a lot of buffalo hunting and is also a firm believer in the value of sectional density, heavy for calibre bullets and modest velocity.

And here, as in my e-mails, I again await a reply from Mr Koos Geldenhuys on an explanation for the more than adequate penetration of the 380/375 Rhino in spite of the large (expanded) diameter.

I am also convinced that Mr Koos Geldenhuys is over-involved in ballistic kite-flying and that he has very limited hunting experience.

In my last e-mail to Mr Koos Geldenhuys, I informed him that his e-mails will be given to some of my friends. Chris Bekker was one of them. I did not ask Chris Bekker for any help regarding the argument between myself and Mr Koos Geldenhuys. I did, however, invite Mr Koos Geldenhuys for a man to man discussion on the 380/375 bullet before an audience, which would include regular users of this bullet. Again I never received a reply from him on this invitation.

Lastly, I used the e-mail address of the Big Bore Association of Southern Africa because of logistical problems with my own.

It was, however, clearly stated that the e-mail was sent on my behalf and that the communication between Mr Koos Geldenhuys and myself was our own business. This was the only involvement of BASA in our communication.

Yours sincerely


DR MAURITZ COETZEE

quote:

Originally posted by mehulkamdar:
Posting for Dr Mauritz Coetzee:

He also stated that he was not interested in field results but rather in concrete facts.

WHAT!!

It never ceases to amaze me that quite intelligent and educated people can make such a remark! It seems everything has to be "weighed" to what they have read somewhere; something that they can then quote or prove by proxy..........

If it hasn't been read.... (and we know by admission it sure hasn't been "field" tested!) Then it is passed off as ignorance by said educated one; ignored or slighted, and we all continue to bask in half-truth and more than likely dated "explainations" of phenomenon that some of us indeed want the real answer to!

Experience is the best teacher.......

I can only end by saying that the afore mentioned "concrete" can permeate quietly and painlessly from "facts" to "head" unbeknownst even to the most read recepient!!!!

BigRx

Posting for Chris Bekker:

Mauritz,

Thanks for your reply that we finally have - we know you are very busy and that you have other commitments in various circles. I must agree with you that the following statement is not only remarkable, but perhaps an all time classic .... "He (Koos Geldenhuis)also stated that he was not interested in field results, but rather in concrete facts.

think it would be a great idea if Koos Geldenhuis could address the big bore hunters at the next meeting of the Big Bore Association about the 380 gr .375 Rhino bullet - I will also make myself available for the occasion. We could also extend an invitation to Doctari. My guess would be that it would be a very humbling experience for Koos, as he is not a buffalo hunter and as such he has not tried the bullet on buffalo. Talking to an audience of buffalo hunters as confidently as he wrote to you would indeed be a very remote possibility! It is quite funny that Koos can have such strong convictions/misgivings about this bullet, based on theory and perception rather than field tests, which are the real tests.

think the time has also come that we should address wound channels created by this very bullet that mushrooms up to 27 mm vis-a-vis other solid bullets, including flat noses. Mark Radloff (PH) remarked in his article the visible effect of the Rhino bullet in comparison with other bullets he and his clients used before.

What has not been discussed before properly is the trade-off between penetration and the size of the hole and that will bring us round to your question that Koos has not answered, as to what is acceptable reduction in penetration in buffalo hunting and how a bigger hole through the heart of these beasts puts them down much quicker. Katte Katzke (PH), another experienced buffalo hunter, is also hereby invited to share his experience with us on this very issue.

Regards
Chris

I refer Dr Mauritz Coetzee to my post dated 21 April 2005 in this category of the forum and specifically to the following part thereof:

quote:

2. From your posting I again saw how sly and underhanded your friend Dr Maurits V Coetzee really is. Trust he has shown you ALL his replies on my letters to him - if he did I trust that you agree with the Big Bore Association that his extremely, shocking and vulgar language used in these replies, is totally unacceptable to all civilized, human beings.

Then more to the point, novice certainly as far as big bore rifles and buffalo hunting goes, but one doesn't need to be a buffalo hunter to know the difference between good, bad and excellent, totally reliable bullets like the GS Custom HV's certainly are.
I have been hunting antelope like Kudu, Gemsbok, Bluewildebeest and Eland for many years with all types of bullets.

As to my hunting experience, many of the above mentioned hunting was done on our family farm in the Ellisras area which my late father owned since 1969 and our family still to date.
Só, judge for yourself the level of experience I have with far more than the usual annual hunting trip to gain experience over a period of 35+ years.

Also refer my post dated 27 April 2005 and I quote:

quote:

Chris, with all due respect, you have pulled yourself down to the level of your friend thru this whole process, which is completely unacceptable to me.
I would therefore no longer take part in this mud throwing on this site where I was " inadvertently caught up in a third party argument" as it was correctly stated by '500grains' earlier on this page.
Furthermore, this discussion, if one dare call it that, is of no use to any of the members or visitors of this web site.

Should you still wish to communicate with me on this topic, I suggest that you get my e-mail address from your very close friend.

No further comments need to be made if you follow the threads on all this below standard junk.

Koos Geldenhuys.

If all of the participants in this discussion will agree to go to a pub and punch each other until the issue is resolved, I will pay for the beer.

Posting for Chris Bekker:

Hello 500 Grains,

Slowly, slowly now bud. Who will pay the ambulance and the casualty ward fees? Remember it is one of our freedoms to differ, even if one is as stubborn as a mule. When Gerard does not agree with you, he will refer to your stuff as garbage, etc. That is fine, because Gerard smells like roses and he does not cheat ... or does he?

Koos made a blunder to throw his theoretical conjecture at an experienced buffalo hunter and as a bases he used Gerard Schultz's ideas to sell his point of view to Mauritz. Acting in such a 'clever' way with Mauritz, having seen 140 buffalos fall to different kind of bullets is rather presumptions to say the least when we consider that Koos has not shot 1 buffalo. Unfortunately, there is a principle involved here, as well as hard evidence from the field that is being ignored, and therefore we cannot let this matter just slip by because Koos is a nice guy or perhaps from royal descent.

We should grant Mauritz the right to answer Koos after he cleared his throat in the way he did. Please don't fotget that Koos wrote Mauritz 3 letters insisting that Mauritz was wrong and that he does not understand ballistics,etc. I mean Koos no ill will, but we have to prevent wrong perceptions getting entrenched that the 380-gr Rhino bullet is not ideal for buffalo when in fact most buffalo hunters will testify to the opposite. That is the debate and the debate alone and not the apparant bad language. Cowboys don'y cry over little things like this.

Field results will remain the ultimate test and we would love to share these results with Koos (no pun)

Regards
Chris

quote:

Originally posted by Chris Bekker:

Who will pay the ambulance and the casualty ward fees?

You guys don't punch that hard do you?

If you get some field results with the bullets in question please post them. There just isn't enough good field data being shared, IMO.

This is how it all started with Mauritz Coetzee's article he wrote.

quote:

In this article I mentioned that the 380/375 Rhino bullet with an expanded diameter (an average) between 24/25 mm creates a massive wound channel and enough penetration due to its high sectional density.

Refer Mauritz's post on this forum dated 22 May 2005 confirming his above statement.

In my mind he misinterpreted, and still does, the bullet's success with his theory of 'high sectional density'.
Simply because momentum drives the bullet or keeps it going all the way!!! DEFINITELY NOT SECTIONAL DENSITY!!!!!
Sectional density is there and will always be, it's like a freshly picked Marula fruit with a pip in the middle - never without it!

Momentum is bullet weight multiplied by bullet velocity.

Now with that in mind, if a .375" bore diameter bullet changes on impact or very, very shortly thereafter into an object of 24/25mm diameter (25.4mm = 1 inch), (now having a 2.67 times bigger resistance area to overcome than the original bore size), PLUS the fact that the velocity is after travelling some distance towards the target - even before impact - already lower than it was at the muzzle, then obviously - even with a possible 100% weight retention - and whatever sectional density you can come up with, the result namely MOMENTUM must be lower than at the muzzle and much lower on impact or very, very shortly thereafter. There is absolutely no doubt about this fact.

This was the question I confronted Mauritz Coetzee with which he refused to answer or admit that my reasoning is correct.

He then started pulling very 'cleverly' tons of other arguments into the debate which in my opinion was an effort to cover up his blunder.
Hence my statement to him that I am not interested in field results untill such time as he has answered my very simple question.

I agree wholeheartedly, Cowboys don't cry, but don't swear at me once you are in a corner due to your own stupidity an inability to admit it!!!

What really bothers me in all this is that you, Chris, must be fully aware of your close friend's blunder (seeing that you have read all the e-mails between myself and Mauritz) and yet you first try to get a shot in on Gerard and now that you have failed miserably with that you both are turning back on me.
Both of you jumped to unverified conclusions like that I was doing Gerard's dirty work for him and having very limited hunting experience.

You were both proved completely wrong with these conclusions - what a monstruous blunder!

How do you two expect anybody to believe anything you are going to say in future?
There will always be a tongue in the cheek considering moment to decide is this the truth or garbage?

As for the field results, I have no problem with that although I have through all this also noticed that the Rhino bullets used to shoot buff with are in most of the cases recovered out of the carcases.
Wonder why they don't exit if

quote:

the bullet provided more than enough penetration and impressive wound channels

????

Just a thought!

Koos Geldenhuys.
PS I trust this will correct any previous wrong perceptions and prevent any future ones on this topic.

I really don´t understand some discussions at the AR forums. Guys are hair splitting and argueing one dimensional or mixing up things which are irrelevant.

In this thread, both parties are a little right, because momentum as well as sectional density are proportional to the penetration ability of bullets.

A basic number for penetration (not considering at the moment drag, nose shape etc.) is the momentum density.

This M/area is proportional to momentum if you apply it to bullets with near the same diameter and also proportional to the SD for bullets with the same velocity.

And if you breakdown v.Alphin ´s penetration index, it is also reflecting the momentum density.

IMO, the 380 gr. 375 is over the top, I couldn't find a suitable American powder to get enough velocity in my 375 with that bullet..without serious compaction...

I decided the 350 gr. was the better route in a properly shaped bullet at near 2400 FPS..

If I need to try and make a 416 out of a .375 then I will use a 416 or 404...

this thread is et up with therory and balistic jargon, that means little in the field IMO...but if thats your thing then have at it, but I wouldn't get my shorts in a wad over it.

Posting for Chris Bekker:

Hello Ray,

There is indeed a lot of jargon being thrown around on this site and strangely opinions also vary quite a bit as to what we experience in the field, which actually makes this whole thing even more fascinating. Interpretations differ and so does perceptions.

My opinion is that the Rhino 300 grainer is a very good all-round bullet in the 375 H&H and also adequate for buffalo, but those hunters that used the 380-gr Rhino bullet will all tell you that it puts buffalo down much quicker.This is due to the bigger hole through the vitals as this bullet mushrooms to a bigger diameter. The fact that the 380 grain bullet is loaded to 2,180 to 2,220 fps (with SA powders) in no way distracts from its lethality - on the contrary it works like a charm. {As a side note, the old British Nitros did around 2,150 fps and was effective with 'solid' (FMJ) big bore bullets}

Buffalo hunting happens at close range and the truth is we do not need the velocity of 300 grainers at 2,400 to 2, 500 fps or as some dudes who like to push it to 2,600 fps. Truth be told, the low-recoiling 9,3 mm 286 gr Rhino bullet at 2,220 fps is putting buffalo down very effectively - in my opinion better than a 300 grainer at 2500 fps. Why? Bullet performance on a tough hardy animal is better at 2,200 than at 2,500 fps - this is a fact proven over and over with expanding Soft bullets. In fact Katte Katze will tell you that he only loads his 416 Rigby to 2,220 fps, using 430 gr Rhino bullets and it works with devastating effectiveness.

Look again at Rob Duffield's 380 grain Rhino bullet retrieved from a buffalo and the buffalo in the second picture (just so Koos cannot say we lie). Incidentally, Rhino Bullets do offer a 350 grainer in .375 as well - it is of the same length, but in semi-spitzer shape instead of a round nose. That means the velocity differential is only 50 fps, as the the powder erosion in the case is very similar. Not enough to hang your hat on. (Will I swap a 350 gr Rhino for a Woodleigh ... never! Is the 350 gr Woodleigh good ... yes! Why is the 350-gr Wdl better than the 300-gr Wdl ? ... the answer lies in the lower velocity that makes the bullet stay together better.)

There is a trend in many calibers to offer heavier bullets, but since one can never catch up to the bore size of the bigger caliber, the only way to increase momentum is to up the weight, and the reason why it works so well is because the velocity comes down, and in terms of the strength of the bullet (or its propensity to shed weight), we find that it works much better. This is not an opinion, its is a proven fact. Do this simple test with your 375 H&H - shoot into a simple wetpack - one bullet at 2,500 fps and the other one at 2,200 fps. That will make the penny drop for the non believers. Do this with Woodleighs, TBBC's and Swift-A Frames - the result will repeat itself with regular monotony.

Just in case some readers have forgotten when I first placed the pictures of Rob Duffield (PH) - he loaded his bullets to only 2,055 fps - far below the average of 2,200 fps .... and ? .... and ? ... the bullet is still devastating. If this does not tell the story of the bullet then I do not know. I can only agree with 500 grains that we aught to share experiences like this with each other to a greater extent and this is the very reason why I started the thread on the 380 gr Rhino bullet.

Take care and best regards
Chris

This is a silly bunch of marketing hype.
.375 caliber bullets should only be made in 300 grain weight.

.

In the USA you can buy Rhino bullets from Bill Isenbarger in Texas. His contact info is on the Rhino website.

here we go again...


based on facts alone, that I think no one will argue with ,along the entire flight of a "normal" hunting bullet, momentum varies with velocity, but SD and construction remain constant.


Myself, I prefer to focus on base facts, and *I* choose to look at construction and sd... others may choose to look at Momentum....


it all boils down to common sense, gents, if you want a bullet to penetrate use a large bore and heavy for caliber bullets at moderate velocities.

Actually the Rhino looks quite similar to the old Bitterroot bullet, which was very well respected in the field.

500 Grains,

Actually the Rhino makes me think of a Barnes X with the inside of the cavity like with lead.

Mike

quote:

Originally posted by Atkinson:
IMO, the 380 gr. 375 is over the top, I couldn't find a suitable American powder to get enough velocity in my 375 with that bullet..without serious compaction...

I decided the 350 gr. was the better route in a properly shaped bullet at near 2400 FPS..

If I need to try and make a 416 out of a .375 then I will use a 416 or 404...

this thread is et up with therory and balistic jargon, that means little in the field IMO...but if thats your thing then have at it, but I wouldn't get my shorts in a wad over it.

Well a person could always make up a Duo Diameter /Bore Rider that would let a person seat the bullet out farther and let you use heavry bullets but at some point thay would become hell to feed into the chamber.

In a double thay would be sweet 380 and 400 grain Duo Dimeter/Bore Riders.Just so happens i know a gent that makes Duo Diameter bullet's
Hummmm O wait that would be me .

Thanks anyway Alf, but no thanks. There is nothing as satisfying as a 300 grain .375 of proper construction and velocity for the job at hand. No others need apply, unless you just want to fool around with something different for kicks.

After returning from our local shooting club's range this afternoon, I paged through the June 2005 edition of 'Game and Hunt' and came across an article written by Dr Mauritz Coetzee.

It was about his friend Hennie Boshoff's second buffalo.
The similarity in the story of this article reminded me of his friend's first buffalo and I went back to the January 2005 edition of the same magazine in which the first article was published, also by Mauritz.

What striked me was that in both cases Hennie used Rhino bullets (535gr and 540gr respectively) in his 500 Jeffrey and twice in a row these bullets failed to put the buffalo bull down. In both these hunts their mutual friend Hanke Hudson, according to Mauritz, had to put the buffalo finally down with two successive shots each time out of his 470 double with 500gr Swift A-frame bullets.

The following comment is purely based on Mauritzs' own field results, no ballistic jargon or any hidden meanings attached to it:
Hennie must have realised by now that the Rhino bullets used in his 500 Jeffrey are not capable of putting a buffalo bull down with the first shot.
Looks as if he should rather switch over to Swift A-frame bullets for future buffalo hunts.

The actual reason for this post is the following:
In the January 2005 article Mauritz stated the following, directly translated from the original Afrikaans article - 'Over time the collection of data regarding bullet performances on roughly 139 buffaloes, gave us some definite thoughts on the hunt of these wonderful animals.'

That made me think and if we take that his friend's Hennie's first buffalo took it up to 140, the mystical figure that Chris Bekker is bragging so much about, probably now 141 with Hennie's second buffalo, how many buffaloes did Mauritz himself actually shot?

It should be of great interest to hear how many buffaloes Mauritz and Chris each shot themselves and also what rifles were used as well as bullet types.

mehulkamdar,

Just one question: In this and other threads I've noticed that you frequently post "for Chris Bekker". Does Mr. Bekker not have a computer? If not, how does he communicate with you? I'm just wondering why he doesn't post on here himself.

Thanks,
-Bob F.

BFaucett,

Mr Bekker has had a problem logging in to Ar with his computer. The administrators tried to help but for some reason he has not been able to do this.

Yes, we do communicate on e-mail and I post his mails herebecause he is unable to.

Posting for Chris Bekker:

Rip,

You say ... "This is a silly bunch of marketing hype. .375 caliber bullets should only be made in 300 grain weight" (SD = .305)

Marketing for who ??? I am a user not a business man, unlike your friend who runs a campaign. Hype ... nope !!! Just the bare facts. In the context of buffalo hunting the heavier bullets work better with SOFTS, as astute people do recognize fragmentation and over-expansion tendencies. It is that simple ... that extra 200 to 300 fps will do you no good, in fact it works against you. Being a convert to the new set of rules of GS Custom (SD is of no concern) you should be punting 150 grainers in the .375 H&H to give you the edge and not 300 grainers. It sounds like you have revised your system of ... "Use a simply dumb SD of 0.3 or as close as possible with available bullets. The SD's significantly higher than this are more than simply dumb, they are then stupid." ... Quote.


However, for hunting of other big antelope at longer distances, the 300 grain .375 bullet comes into its own. Here, a good case can be made for a semi-spitzer at 2,500 fps to achieve less bullet drop at longer ranges ... the qualification is always the APPLICATION. My son shoots the 300 gr Rhino semi-spitzer exclusively, as he only hunts kudu and blue wildebeest with it ... and another thing ... he gets comfortably by with 2,350 fps (his father's influence), by just zeroing 1.5" high at a hundred and he can take shots out to 200 yds if need be.

Jeffeosso,

You say ... "I choose to look at construction and sd" ... nice observation buddy. Pushing a bullet beyond its threshold strength for the sake of maximizing MOMENTUM is as silly to scratch one's ass when one's head itches. Extra velocity becomes self-destructive if bullet construction is not taken into account. Like I said above, my son shoots 300 gr Rhinos @ 2,350 fps. Why should he shoot solids/monolithics at 3,000 fps to come even ( being over generous) at the cost of higher recoil and the possibility of an induced and incurable flinching.

Take care
Chris
"NILS ILLEGITIMAE CARBORUNDUM"

Chris,
.305 SD is close enough to .300 for RIP work. Don't nit pick just to have something to argue about. If the SD were 0.295, that would be O.K. too. I find SD a FOM of limited descriptive utility, a paraphrase of reality, close enough for RIP purposes. It is not nonsense, just doted on too much by others, not me.

Actually I am in the middle here between the extremes of you and Gerard.

I had to pester him a long time to make some of those .375/300 grain FN's and HV's. He kept trying to push the .375/270grFN/265grHV. I much prefer the slightly heavier and slower .375/300grainers, which do have higher BC, which may be of some importance occasionally.

I will never buy another .375 bullet that does not weigh 300 grains.

The only good thing about having some of the 270 grain FN's is that their nose shape is the same as the 300 grain FN's, for the Steel Maiden tests upcoming.

Chris,

Are the jackets of Rhino bullets PURE copper?

And are the cores PURE virgin lead?

Posting for Chris Bekker:

Hunters,

Pressure tests with 380 gr Rhino bullet

I hope SA Reloaders will find the following info helpful - Results of pressure tests done at the SABS lab - Rhino bullets in 375 H&H:

Bullet ---- Powder ---- Load ----- Velocity --- Pressure
300 gr ---- S365 --------- 63 gr ------ 2,428 fps --- 57, 217 psi

Bullet ---- Powder ---- Load ----- Velocity --- Pressure
380 gr ---- S341 --------- 64 gr ------ 2,223 fps --- 63, 017 psi
380 gr ---- S335/365 --- 32/32 gr - 2,223 fps --- 61, 103 psi

For a lower pressure level one can drop down by 2 grains to achieve 2,153 fps:

Bullet ---- Powder ---- Load ----- Velocity --- Pressure
380 gr ---- S341 --------- 62 gr ------ 2,153 fps --- 61, 048 psi
380 gr ---- S335/365 --- 31/31 gr - 2,153 fps --- 59, 193 psi

Clearly there is a difference when compared to the 404 Jeffery's internal ballistics. The bigger bore and longer freebore of the .423 caliber operates at a much lower chamber pressure than the 375 H&H and the same is true for the 416 Rigby with an even bigger case.

The 404 and the 416 was designed for tropical areas to keep pressures down - such as the Zim valley where temperatures can easily reach 40 degrees C as opposed to the 28 degrees of Johannesburg. You just cannot make a 404 out of a 375 - the physical laws will prevent you.

By design, even with 300 grainers @ 2500 fps, the 375 H&H is a high pressure cartridge. This aspect is sometimes overlooked when we just focus on external ballistics. What is more ideal than a .423 bullet at 2,250 fps for dangerous game hunting with present day premium grade bullets? You simply don't need any bigger or faster!

Ballistic balance is the ultimate criteria in my opinion in a well designed cartridge - some cartridges coming to mind are - the 7 x 57; 9,3 x 62; 404 Jeffery; 416 Rigby and the 500 Jeffery. If you prefer a K98 action like I do, then pushing the pressure envelope is not on the cards. With modern actions we can shift the goal posts a bit, but I am not prepared to dump my Mausers for that dubious benefit.

Chris
"NILS ILLEGITIMAE CARBORUNDUM"

quote:

Originally posted by 500grains:
Chris,

Are the jackets of Rhino bullets PURE copper?

And are the cores PURE virgin lead?

Posting for Chris Bekker:

500 Grains,

Both the copper and lead used in making Rhino bullets are "pure", as they flow better together during expansion. The combination of gilding metal (90% Copper & 10% Zink) and conventional lead cores (97% lead & 3% antimony) do not work so well. The antimony in the lead makes it more brittle and is thus not ideal to flow with the copper on expansion. Also, the copper gets annealed to increase its malleability, making the bullet stronger so the petals don't tear off. However, gilding metal fouls less.

Rhino Bullets make the copper jacket from solid bar. It gets drilled to give thick walls. The walls get thicker as the caliber gets bigger to cope with higher energy values. Then lead core is bonded to the copper walls, which also strengthen the petals during expansion as thick layers of lead flow when the bullet opens up. The copper jacket tapers towards the front, and the big-bore bullets get guided at the tip so that bullets can expand from as low a velocity as possible.

Finally, all bullets go through a number of finishing dies at the end to ensure that they are within the CIP specification and to ensure consistency in accuracy, as much as can be expected from a hunting bullet. Half a minute of angle groupings are quite common in my Custom Mausers. The bullets are moly-coated to lower the chamber pressure and to reduce barrel fouling. Quality control is an important element in the production process and that is why it stands under Kobus' direct supervision - not some cheap uneducated labour.

I will be posting some sectioned bullets for you in .375 and .423 calibers shortly, so you can see the construction a bit better.

Chris

quote:

Both the copper and lead used in making Rhino bullets are "pure", as they flow better together during expansion. The combination of gilding metal (90% Copper & 10% Zink) and conventional lead cores (97% lead & 3% antimony) do not work so well. The antimony in the lead makes it more brittle and is thus not ideal to flow with the copper on expansion. Also, the copper gets annealed to increase its malleability, making the bullet stronger so the petals don't tear off. However, gilding metal fouls less.

Rhino Bullets make the copper jacket from solid bar. It gets drilled to give thick walls. The walls get thicker as the caliber gets bigger to cope with higher energy values. Then lead core is bonded to the copper walls, which also strengthen the petals during expansion as thick layers of lead flow when the bullet opens up. The copper jacket tapers towards the front, and the big-bore bullets get guided at the tip so that bullets can expand from as low a velocity as possible.

Finally, all bullets go through a number of finishing dies at the end to ensure that they are within the CIP specification and to ensure consistency in accuracy, as much as can be expected from a hunting bullet. Half a minute of angle groupings are quite common in my Custom Mausers. The bullets are moly-coated to lower the chamber pressure and to reduce barrel fouling. Quality control is an important element in the production process and that is why it stands under Kobus' direct supervision - not some cheap uneducated labour.

So ? how thick of a wall are thay .. do thay very in the same diameter can i get a 0.040 jacket wall in a .375 and a 0.050 in a .375
and a 0.0650 jacket wall ? .
And i understand about the C220 fouling less
but in a thinner jacket 0.020 in C220 works out about the same as a 0.035 Copper jacket and you get less fouling although there much harder to swage out then the copper jackets.

Now ? who is it that makes the Rhino Bullet's.

Thay sound very good . do you have a link to there home page .

Thanks ahead of time
Martin

If my reply to Chris does not interest you, do not click on this link.

Chris,

How do you go about making a section of a bullet? I have not found an easy way that is not extremely time consuming.

Jagter

It seem to me that you have a problem with Rhino bullets in general,as you mention in your last post about the 500JEFF bullets that Hennie Boshoff used.

I have hunted 7 Buffalo bulls over the last 5 years in Botswana, Zim, Tanzania and Rsa.All of them were hunted with my 500JEFF using Rhino Bullets,only the first one was shot with a Woodleigh FMJ,i lost this buff wounded not to bullet failure,but to bad shot placement,as was the case white hennie's buffalo.

All the other Buff were one shot kills,with pictire pefect mushroom Rhino bullets found on the oposite side under the skin.

So please do not Confuse BAD SHOTPLACMENT Whith Bullet Failure.

Regards Jaco Marais

Jaco, I'm so glad you came forward on this subject on AR - you're like a fresh morning breeze with your realistic views and honest field results!!!

quote:

I have hunted 7 Buffalo bulls over the last 5 years in Botswana, Zim, Tanzania and Rsa.

Even a blind man can sense that these are realistic figures!

Thanks for mentioning bad shot placement. Just think how much more BS would have flown around on this forum from the twins if I had mentioned that, although I itched to did just that on many an occasion.

I can assure you I have no problem in general with Rhino bullets, never used them and doubt if I ever would, it is the people presenting reports and articles in totally unacceptable ways, expecting their readers to swallow it all without any questions being asked, that makes me fed up.

quote:

Originally posted by 500grains:
Chris,

How do you go about making a section of a bullet? I have not found an easy way that is not extremely time consuming.

Posting for Chris Bekker:

500 grains,

To section the bullets with handtools come down to doing it very carefully. You need to file it down. Putting some chalk onto the file helps to get a smoother surface. Do not put the bullet unprotected in a vice, as it will leave ugly indentation marks. I normally ask a friend of mine to do it for me, as he is a tool and die maker. I have given him some bullets to section for me, which I should have during the next day or two. Then I can take pictures and post them. You could also section bullets with a wire EDM machine at an engineering shop, if you want neat work.

Unlike TBBC's, the Rhino's are not designed to always yield a fixed ratio of copper to lead like 70:30 or what ever it actually is. For example, even in the same caliber say 9.3 mm, we find that ratio's differ between the various weights on offer - that is why the 300 grainer mushrooms to a wider diameter than the 286 grainer. The 300 gr RN bullet in 9.3 is driller much deeper than the 286 gr bullet as they are essentially of the same length. Both perform well on buffalo, but for game hunting the somewhat higher velocity and flatter trajectory extends the reach in practical terms. Needless to say 14 grains of weight differential is not a big issue.

I will post shortly a .375 caliber 350 gr bullet in Semi-Spitzer configuration and a .423 caliber bullet in a RN version. Also a 286 gr 9,3 Semi-Spitzer bullet that was retrieved from a wetpack - I am particularly fond of this bullet.

Take care
Chris

Posting for Chris Bekker:

Gerard,

Gerard, you should make a fine teacher at a kindergarten. Take 10, then add 12 and draw the square root and add your street number to it to get the answer of the bakers dozen - if it is too difficult to calculate, then throw the 10 and the 12 up into the air and ask your cheerleaders to help you catch one of the marked marbles coming down. If you are not still happy with the result, repeat the exercise until you are happy and then announce it to the world that you have cracked the mystery.

Rather than to worry about the 'baker's dozen', I suggest you correct your skewed comparison on your website, as to how much less winddrift the HV bullet has against a Round Nose bullet (175 gr in 7 mm) at 300 yards - nobody hunts with heavy for caliber round nose bullets at that range, but if you have to do it, then please pick a Nosler Partition 175 grainer that has a spitzer point. That would be far more equitable than the garbage you dished up for us.

I further suspect that the calculations are as suspect as when you tried to cheat us last time here on the forum. If you do in fact compare the Nosler Partition 175 gr bullet with the HV bullet at 300 yards, then the differential winddrift is a mere 1.44" in a 25 km/h wind (9.56" vs 11.0") - I guess nobody but you would hang his hat on that ! Furthermore, it borders on insanity to shoot animals at 300 yards in a wind of 25 km/h.

Get real, otherwise don't go into teaching, rather opt for being a magician so you can pull the wool over people's eye's !

Chris

Well I don't necessarily disagree with any of this and I do like the 350 gr. bullets in the 375 H&H for use on Buffalo..

My complaint with the 380 gr. is it simply takes up too much powder space and keeps velocity down too much for my liking...if I am going to shoot something at 2100 FPS, then I want a bigger cross section of bullet not a longer bullet...a 40 to 47 cal. is more to my liking at those velocities with heavier bullets..The 380 gr. is like trying to make a silk purse out of a sows ear...

To suggest the 380 grs kills any better than a 300 or 350 is just in the mind of the shooter, I have shot too many buffalo to buy off on that, and when one get the expansion you refer to then penitration suffers and I still like two holes in my buffalo...

The added velocity of the lighter bullets within this scope of weights we are discussing here creates more internal trama IMO...

Again, moderation is the clue...you can go over the top in both directions IMO...

Now this is only my personal opinnion, based on my personal experiences and it may or may not be totally correct, but I think it is today, maybe I'll change my mind someday, who knows.

Posting for Chris Bekker:

Martin,

The copper jacket walls get thicker as the calibre gets bigger, as they carry higher energy values - for example:-

Bullet Wall Thickness Percentage

458 - 500 Gr 2.82 mm 259%
375 - 300 Gr 2.26 mm 207%
308 -180 Gr 1.41 mm 139%
270 -150 Gr 1.91 mm 175%
243 -100 Gr 1.09 mm 100%

Rhino bullets are made by Kobus vab der Westhuizen - see their website - just search Rhino Bullets and you will track it down.

Chris

Posting for Chris Bekker:



The first 2 bullets are 350 gr RHINO bullets.
The one unfired and the other one sectioned.
Then the 380 gr RHINO bullet unfired.
Unfortunately I no longer have another 380 grainer to section

Reply to Bekker's post of 02 June 2005 20:51

Use the link only if it interests you!

quote:

Originally posted by Atkinson:
IMO, the 380 gr. 375 is over the top, I couldn't find a suitable American powder to get enough velocity in my 375 with that bullet..without serious compaction...

I decided the 350 gr. was the better route in a properly shaped bullet at near 2400 FPS..

If I need to try and make a 416 out of a .375 then I will use a 416 or 404...

this thread is et up with therory and balistic jargon, that means little in the field IMO...but if thats your thing then have at it, but I wouldn't get my shorts in a wad over it.

I think Ray's comment makes sense, I also believe a 350 gr is a better choice for a .375 H&H Cal.

Roland

Posting for Chris Bekker:



Here are 2 sectioned .423" bullets. The one on the left is a 400 gr Rhino bullet. The one on the right is a 400 gr Stewart bullet.
The Rhino is made from copper bar whereas the Stewart is made from bronze. Both are bonded bullets, except the Stewart does not have a solid shank. The Stewart bullet is the 'Hi-Performance' version featuring thicker jackets intended for bigger game. Both are strongly constructed bullets as one would expect to find a DGR such as a 404 Jeffery.

Chris