quote:

Throwing out stuff like the Navier-Stokes equations for the momentum of fluid flows doesn't really bring anything to the table.

Yeah, but ya gotta love that Tech-talk!

/

quote:

Originally posted by Rusty:

quote:

Throwing out stuff like the Navier-Stokes equations for the momentum of fluid flows doesn't really bring anything to the table.

Yeah, but ya gotta love that Tech-talk!

The Navier-Stokes equations are three equations that define the conservation of momentum in terms of the fluid viscosity, density, and the velocity in three dimensions, which in the case of Cartesian coordinates are typically noted as u, v, and w velocities.

Used in conjuction with the continuity equation (conservation of mass), the four equations can be used to solve simultaneously for the velocities (u, v, and w) and the density.

I think that pretty much explains it all.

Alf,

Lighten up. I'm just kidding you.

It is all in the overturning moment.

That is why Flat nosed bullets penetrate deeper.

Is it GS that states the slight boattail increases penetration with his bullets??

As there is a slight taper toward the nose the reducdion of mass in the boattail helps to stabilize the bullet.
ie less of a tendency to overturn.

The proper twist is a factor as well.

I don't know. I think all of the input is good. If you want to ignore it you can. If you want to know more about it, you have a starting point.

If I recall correctly, Taylor first brought up the issues with the 470. He was comparing it to the performance of his 465 H&H.

In Taylors time, one mostly boought cartridges from the rifle maker. So he was getting his 465 ammo from the best.

There were some chamberings that were not proprietary and released to the trade. The 470 NE was one of them.

Now, people who designed a proprietary rifle around a proprietary round had a great advantage - they knew the capabilities of the rifle and developed ammunition specifically for that design. For those non proprietary rounds, I suspect there was a lot of guess work. And even Taylor acknowledged that the issue with the 470 in his day was probably due to poor bullet design.

I have a 470, and it amazes me at the lack of bullet options. Sure, a lot of people make them, but not in design. For some reason, bullet makers think the 470 is some kind of transition round that requires a sharper taper.

It is not a long range bullet. It is a DG round. Now, I don't proclaim to know an ogive from any other kind of jive, but it is important. And where you put the ogive plays hell with center of gravity.

For longer range, the bullet needs to be more aerodynamic. So the tip gets tapered soemtimes into a point and the ogive (my understanding, where the "taper" stops) is moved back from the tip. Whenever you take more off the top, there is more on the bottom to get the required weight.

And more on the bottom for punching power is not a good thing.

Based on my dangerously low level of knowledge here, I may be way off base. But I don't think I'm that far off.

Try a couple of little experiments. With only your index finger, throw a punch with only your index finger contacting what you are hitting. You target should be something other than your significant other, best friend etc. The result is that you are probably going to break your finger. All that energy is wasted.

Not so with your fist. Since the size of your closed fist is roughly equal to or slightly less than the round measure of your forearm, that energy is going to be focused along the broad line of your fist.

Excuse me while I wakje the Fed X guy up....

Ok I'm back. Hey, I'm Irish, and we only use analogies that we test!

Another one. Take a spire point bullet, hold it by the base and try to drop it on its
tip a couple feet off the ground. The bullet lands base first. (This is a fascinating experiment after a few drinks). Next take a blunt or flat nosed bullet and do the same thing. Interesting. The Fed X guy is still out, and his forehead makes a great platform...

I am now looking at 4 different factory loaded soft 470 rounds: Federal, Knyoch, A-Square and Wolfgang Romey. Only A Square has the typical round nosed bullet. Federal has a flat point that cuts to a taper after the ogive about a third of the way down on the bullet. WR and Knyoch have a round nose that gradually tapers to the crimp line.

What does this tell me? It tells me that the only way I am going to realize the potential of a 470 is to reload using bullets with a nonimal ogive. A bullet that "gets fat" right away.

Now, if you will excuse me, I have to drag the Fed X guy onto my neighbors lawn....

so, what's the twist of dan's 505 gibbs and if it was faster, would it penetrate better?

just basic questions, prior to listening to further groans of pontification.

jeffe

does the twist of the bullet slow down significantly at 50 yards 100 200 300???

i am sure bullet weight and velocity is a factor.

boomy,
on the article showing the penetration of the various .308 bullets, the gent raises an interesting point... DIRECTIONALLY (from memory, so not anything like exact) a bullet fired at 241krpm slowed to like 210K rpm at a distance, but if the rifle where fired at that distance speed, the RPM was something like 178kRPM... yep, it slows, but NOT NOT NOT as a function of speed, as it is a "weak" force... however, if fired at a lower speed, the RPM is lower...

or, to answer your question, some, but not much

jeffe

Thanks for all interest, but after two pages, nobody have given any information about theese rumors of the .470's limited pentration. Not even Dan, even if he has several contributions and my question was mostly directed to him.

But ALF, thanks again for interesting information.

Bent,

Don't hold your breath.

A single, dated reference to rare (3 shots over the course of shooting over 100 elephants) penetration problems with the .470NE does NOT translate into an 'OK reputation for penetration', no matter what someone here says.

You must, as always, consider the source of such unadulterated bullshit generalizations.

George

C'mon Bent,

you have to consider the source, versus a hundred years or so and thousands of elephants killed by regular human beings.

Rich
DRSS & NRA Life Member

/

The tooth paste effect described by Alf was not retricted to the 470 caliber. In Jose Pardal's book "Elephant Hunting in Portugese East Africa" he shows a page full of bullets from the following calibers: 470, 475 no.2, 450 # 1/4", 425 Weatley Richards, 450/400 3", 404 Jeffery, 375 H&H and 9.3x62 Mauser. All calibers show this same affect. As an example he shows 7 recovered bullets from the 450/400 and two show greatly flattened bullet bases. The problem was with the old cupro-nickel bullets having insuffecient shielding. Once kynoch went to steel jacketed solids bullet deformation was greatly reduced. Taylor shows drawings of 500 Jeffery solids that were recoverd from elephants. all showed what we would describe as bullet failures. With modern bullets either steel jacketed as Woodleighs or monometals bullet failure is very rare. The 470 is or was no more prone to bullet failure than any other caliber using the same bullet construction.

465H&H

465H&H,

Some solids still do the toothpaste routine though nowhere nearly as badly in the "olden days."

I think the limited penetration that I have seen is that the larger diameter bullet, as compared to the 416's as an example, just needs more velocity.

I wunged off a couple using 500 gr. Wooleighs and H8831sc this morning that regulate well at R:2194 fps and L:2165 fps. How much differenc that this will make over the nominal 2125 fps I do not know but it can;t hurt any.

The North Fork solids got too fast, in the low and mid 2200's. I'll have to tone them down some, but with all the hype on FP bullet penetration, I figure I can drop three elephant and a couple buff with one shot using that load, assuming they cooperate and line up correctly.

Hell, Taylor did it on buff didn't he?

/

Since we would never use the old Kynoch bullets it is a somewhat academic discussion. I'll try to get Terry to post the pic from Pardals book for me here. Have patience!

465H&H

465: I have Pardal's book. IF you can't get Terry to do it, I can get it scanned and posted. jorge

jorge!

I asked Terry to post one page, the one with the nitro express bullets. I think it would be of value if you could post all of the pics of recovered bullets. The page with the pictures of early and late sectioned Kynock bullets is especially interesting. Thanks!

465H&H

I'll try and do it over the next couple of day. jorge

Jim Manion,

Taylor's comments about the failure of the 470 bullets to deliver straight line penetration was a comparison between the 470 and the 465 but also the 450 No2 as he mentions in the passage. He shot half again as many elephants with the 450 No2 than with the 465 to boot. The 450 No2 is not a proprietary round but it does have the hemisherical bullets, the lack of which seems to have been the 470's weakness.

The common denominator is the bullet shape.

Will,

You will love the North Forks. The .474" North Forks are 500grs, IIRC. At the same speed as the Woodleighs there will be no comparison.

JPK

No offense but who gives a crap about what happened 100 yrs ago with crappy Kynoch bullets? The point being that the .470NE with good modern FP bullets PROPERLY CONSTRUCTED will kill anything that walks this earth with EXCELLENT penetration with its 1:18 twist! It has an excellent reputation and to claim otherwise is just plain Stupid. As much as I enjoy blasting big gaping holes through things, truth is the .470NE is more than enough gun!?-Rob

quote:

Originally posted by GeorgeS:
You must, as always, consider the source of such unadulterated bullshit generalizations.

George

George
i just sprayed a beer on my keyboard!!!

got a spare mickysoft ergo laying around???


Rob,
without a doubt, you are correct.

quote:

Originally posted by Robgunbuilder:
No offense but who gives a crap about what happened 100 yrs ago with crappy Kynoch bullets? The point being that the .470NE with good modern FP bullets PROPERLY CONSTRUCTED will kill anything that walks this earth with EXCELLENT penetration with its 1:18 twist! It has an excellent reputation and to claim otherwise is just plain Stupid. As much as I enjoy blasting big gaping holes through things, truth is the .470NE is more than enough gun!?-Rob

Jeffe,
you got the good part, I just snorted a mouthful of nog 'n grog thru my nose...be happy you are not getting a good visual on that.

Rob,
you are going to develop a complex if you don't stop repressing your true feelings. Don't sugarcoat it man, give us THE WORD!

That is a good question, what does define "bullet failure"? Take solids.

Bullet A penetrates an elephant from intake to exhaust pipe. Elephant kills client and PH before succumbing to wound. Recovered bullet looks as if it could be loaded and shot again.

Bullet B deforms and stops in shoulder area of spine. Elephant falls over dead. Bullet looks like a pancake.

Observation: my favorite bullets are Nosler Partition.
I shoot Elk and Mule Deer with a 300 Magnum, and we usually find the bullet rolled up on the offside under the hide. Expansion is double the caliber or so, and the front section is smashed and fragmented. None of these animals went ten feet. My definition of bullet failure for non-dangerous game is any bullet I don't recover...exit wound = wasted energy.

How does the criteria differ for Buffalo (cape) and Elephant and Rhino?

regards,


Rich
DRSS
NRA Life Member

/

One defense mechanism of the human psyche is to ridicule that which we do not understand, and I see evidence of it in this thread.

Dan- Some understand more than others. That comes from experience and knowledge. To those with a limited intelligence it may seem like ridicule. Its not. You and I both know just how good a .470NE actually is. -Rob

THAT settles it! I am selling my crappy under performing .470 double and buying a Marlin in .45-70 IMMEDIATELY!

I just somehow knew that this thread would get "twisted" before it was all over.

quote:

Since we would never use the old Kynoch bullets it is a somewhat academic discussion. I'll try to get Terry to post the pic from Pardals book for me here. Have patience!

465H&H

IdahoSharpshooter,

Your last post leads me to wonder what your experience is regarding big game such as elephant, rhino and in my opinion buffalo too. I've never shot a rhino but been close.

An elephant is not killed with a typical softnosed bullet and not with a really premium one either, at least not in calibres anyone typically can carry.

Elephant are either killed with a brain shot or a heart/lung shot. You might get away with a really good soft on a side brain shot since penetration requirements are limited. You won't get away with the great, great majority of frontal brain shots where penetration is king. Only the head down, full charge offers an opportunity where penetration nessecity is limited. Even a small elephant is huge and its skin is over an inch thich and very tough, and eleastic to boot. Elephant are easy to kill with a heart lung shot but of absolute importance is straight line penetration. You need to penetrate one lung fully and much better, both lungs. You won't get this with softs so your parrallel is useless.

You don't need through and through penetration on either a side brain shot, a frontal brain shot or a heart lung shot but it is no handicap. It is merely affirmation that when you need to take a shot where the penetration is paramount you have it.

All I have read on rhinos points to the same reality, but again, I've never killed one.

Lots of people talk about a good soft for buff. I've never used a soft, though I would like to try, just to see how they work. With a good shot with a solid, they die very, very quickly. I have never had one even have the time to give a death bellow after being well hit with solids.

Back on to the 470, there were problems in the past and currently with erratic penetration, at least straight line penetration. Better standard solids help, not an issue where softs are concerned, but then for what the 470 is best for softs are not needed. The answer lies with flat nosed solids or even hemishereical nosed solids.

In any case, an expended bullet against the off side is no better and really less effective than an exit in the same circumstances.

JPK

Rob,

One of the issues is velocity. A twist that is fine at 45-70 velocities will, for the same bullet weight, exhibit excessive yaw at 460 wby velocities.

I wonder why the older 470s have a 1:20 twist but some newer ones have a 1:18.

quote:

Originally posted by JPK:
The answer lies with flat nosed solids...

I feel that any big bore can be substantially improved by the use of FN solids.

500 Grains,

I owe you my notes on penetration in elephant heads.

The short version:

.458" 500gr Woodleighs at 2135fps = about 32 - 36" of penetration.

.458" 450gr North Forks at 2190fps = not less than 53" of penetration.

Thats 60% better penetration, 34" vs 53", without any loss of apparent, visible knock down or stopping effect. No gain here either, just in penetration.

Just imagine what a 500gr North Fork out of a 470 would do vs a 500gr Woodleigh at the same velocity - if you have enough twist to stabilize it.

Rich's .474" 500gr Woodleighs at 2250fps didn't quite equal my North Fork's penetration. They tracked true too.

JPK

quote:

Originally posted by JPK:

...without any loss of apparent, visible knock down or stopping effect.

JPK

This is not a criticism but it would be difficult to make this sort of judgemnt without killing the elephant twice.

quote:

Originally posted by 500grains:
One defense mechanism of the human psyche is to ridicule that which we do not understand, and I see evidence of it in this thread.

Sir,

The only thing I see is that even after 5-6 cotributions in this thread you still do not want to expose the sourse of your rumors. Is that a defence mecanism too?
I am not taking side, I am not entering a pissing contest, I just observe that you choose to ignore a smple, direct question.
I find that strange.

I just read an article in the African Sporting Gazette by Terry Wieland I believe on Pondoro Taylor. In the article he refers to Taylor's comments on the 470's issues with penetration and the old Kynochs. Hope this helps. jorge

quote:

Originally posted by Bent Fossdal:

quote:

Originally posted by 500grains:
One defense mechanism of the human psyche is to ridicule that which we do not understand, and I see evidence of it in this thread.

Sir,

The only thing I see is that even after 5-6 cotributions in this thread you still do not want to expose the sourse of your rumors. Is that a defence mecanism too?
I am not taking side, I am not entering a pissing contest, I just observe that you choose to ignore a smple, direct question.
I find that strange.

Bent you have had a burr under your saddle about this from the outset a couple of threads ago. That has been obvious for quite a while. So please don't expect me to go back through several dozen safari books to find the quotes, and I do not take notes as I read recreationally either. Even if I did post quotes for you, I expect your response would be something like "Don't believe everything you read."

Perhaps you can compare the responses in this thread which say "My 470 penetrates great" versus those that say "My 470 had a penetration issue". That is certainly more productive than doing your best to conjure up an argument.

Dan- The only way your going to have any appreciable bullet yaw is 1, if the bullet is not adequately stabilized in the first place. 2. It has internal voids or differences in density that effect the axis of symetry.3. it has slowed down to below spin stabilized velocities and has deformed such that its weight is no longer symetricaly aligned. This will happen if the bullet is deformed upon penetration which of course soft points are well noted for. My point again is I'm talking about .470NE monometal bullets that are concentric and of uniform density. Velocity 2150fps 1:18/ 1:20 twist who cares as long as its enough to spin stabilize that specific bullet design. I've gotten 36 plus inches of penetration in solid oak with that combo and pass throughs on ELE. Does anybody need more penetration than that? Is the .470NE more than enough gun for anything that walks this earth with modern well designed bullets? Lets see the data that says it isn't. Again who cares about the results of old crappy Kynoch bullets 100 years ago.

quote:

Originally posted by 500grains:

Bent you have had a burr under your saddle about this from the outset a couple of threads ago. That has been obvious for quite a while. So please don't expect me to go back through several dozen safari books to find the quotes, and I do not take notes as I read recreationally either. Even if I did post quotes for you, I expect your response would be something like "Don't believe everything you read."

Sir,

Was my question so strange? Did I ask for quotes?

Will you please tell me when ever I did NOT treat you as a genleman?

For certain, you do NOT treat me as one.

quote:

Originally posted by Bent Fossdal:
Will you please tell me when ever I did NOT treat you as a genleman?

For certain, you do NOT treat me as one.

Bent,
this is dan's reaction when pressed to answer factually and irrefutabily, once and for all, on a subject he is certain he is not an expert in.

Don't feel bad, being treated badly by dan just means you are close to allowing him to admit he " doesn't KNOW" something, which he reacts poorly to.

Don't worry, if you ask him 4 or 5 more times, you to will be called a deceiver and added to his ignore list

jeffe