Alf,
my post was not to repeat a presentation of your story.
It was only to show, that references to Kneubuehl are not supporting your ideas and sometimes his propositions are contradictory.

quote:

the current RAAMICS sytems projectiles look nothing like Hansen superpenetrators

They are not hunting bullets, but using the same cavitation bubble for less drag and high penetration. The cavity in some warheads is produced by additional gas injection.

quote:

The current gain in penetration between superpenetrators and simply flat meplat solid without cavitator disks are not enough to be convincing that the process is at work.

Right, if the simple flat meplat is sharp edged and comparable in diameter, the process at work is the same. I published it. You are so fixed on your ideas that you are not able to see what others are saying.

quote:

Secondly I do believe that FN's outpenetrate RN's and ogived bullets in tissue but they do so not because of some vapour bubble or cavity, after all in tissues all bullets move and induce cavities, even the round balls fired from muzzle loaders !
No they do better because the FN remains stable and does not tumble.
If the ogived projectile was stable it would outpenetrate the FN!

Right, exactly you can read it on my website.
But were your shoulder stabilisation comes in?
It is the sharp, big meplat, which stabilizes the cavity, keeping the gyroscopic stabilisation at work.

quote:

The most stable deepest penetrating projectile of all projectiles is in fact the fin stabilized flechette.

No doubt about that. That is why bow hunting works. But we are discussion hunting rifle bullets.

.

Norbert and Alf,

Your discussion is over my head, but I would like to point out two emperically observed and repeatable facts;

1. The Bridger solids penetrated farther in Dans test on elephant skulls than a GS-FN or NF-FN and they have a larger meplat (I think). You may want to confirm this as I dont have any.

2. In my water test using rectangular 18 gallon containers with very little influence from the constainer, mostly water that is, the NF-FN had over 120 inches of penetration!



This compared to an impressive 60 inches or more (three shots) into elephant skull.



I dont mean "to beat a dead horse," but note the larger than diameter entry hole on the elephants head. This shot threw blood splatter on me from 20 feet away.

The NF's were absolutely stable in the 18 gallon water tanks until the very end of the last 18 gallon container. Their bullet path did climb very slightly as if the bullet was creating lift.

The NF's were amazingly stable compared to TCCI-RN which went only 32-39 inches before they exited sideways, and about twice the penetration of the GS-FN which veered off after more than 50 inches.



The TCCI-RN had nearly identical penetration in the elephant skull as in the water tanks. Yet the NF-FN had about one-half, so super-cavitation may be greater in the water for a FN?

It appears these emperical results from the water tanks and Dans elephant w Bridgers do not support what Alf has just said in his last post.

". . . these bullets are free of sidewall friction, ie like a true supercavity only the nose is wetted. In our current FN bullets such as GS and NF the drag on the nose would be dictated to by the size of that flat meplat.

But let us say these bullets with their large Meplats and near cilinder shapes are fired into water ( pure fluid), how deep will they penetrate and how long in the penetration profile will they still have gyro stability?

I think not long and what is more their penetration in water is going to be way shorter than a slender body small diameter supercavitor.

The reason I say this is the size of the meplat.

The drag induced by the large meplat will kill velocity very quickly and the density differential from air to water will kill the part palyed by spin in the equation and yet these projectiles remain stable Why?"

End quote.

Alf, you may want to repeat the experiment before founding a theory on an assumption.

It would be relatively easy to see if the Bridger out penetrated a NF-FN in water despite a larger meplat. But I dont think you will be able to have a verifiable theory re. shoulder stabilization unless you repeat this test for yourself.

As Norbert knows, recovering a FN solid in water is no easy chore, as you can tell from the depth required to stop one in my picture. (That is a 16 foot long flat bed trailer the 18 gallon containers are lined up on). Alf, this is challenging, but I think you would enjoy the experience.

Andy

The Bridger .510's that I tested had the largest meplat of all.

Andy quoted:

quote:

It appears these emperical results from the water tanks and Dans elephant w Bridgers do not support what Alf has just said in his last post.

There are many experimental findings, esp. my results, absolutely contrary to Alfs last post. I wonder, why he is permanently denying this.

.

Alf,

Please spend your time shooting some large animals with FN solids of various meplat sizes and report what you observe. An article reporting the data that I collected about FN and RN bullet penetration was published in African Hunter, and you are welcome to review the article for the data.

quote:

But let us say these bullets with their large Meplats and near cilinder shapes are fired into water ( pure fluid), how deep will they penetrate and how long in the penetration profile will they still have gyro stability?

I think not long and what is more their penetration in water is going to be way shorter than a slender body small diameter supercavitor.

Alf, how do you explain that a NF-FN remained perfectly stable in water three (shots) in a row for such an incredibly long shot path?

10 feet!!!

Just repeat the experiment with your 404. The 380 grain NF-FN has the same SD as my 450 grain 458 and you can acheive nearly identical velocity (2550 fps).

Andy

?

!

quote:

Originally posted by Alf:

500 gr:

?????????????????????????????????????????????

Do you want us the believe that this is the way it is because you reported something you observed under uncontrolled circumstances in African hunter Confused Well I' ll be damned.

Alf,

You repeteatedly insist that we ignore all field experience and instead rely on misplaced and misinterpreted theories that you advance. Personally I find theory that squares with field experience much more convincing.

But feel free to argue theory all that you wish. However, as the universal experience of those using flat nose solids in the field reporting here is that they penetrate deeper than round nose solids, and as you have no personal experience with flat nose solids on large animals, then I think it is time for you to put away your theories and go hunting to find out for yourself.

To paraphrase Andy's advice for you: Hunt more, read less.

]

quote:

Originally posted by ALF:



But you want us to believe based on your extensive experience that the FN bullet with the biggest meplat and most drag penetrates the deepest ????

All I can do is refer you to field results, and to Norbert's website explaining the supercavitation mechanism. When a .375 flat nose is giving me 38 inches of penetration compared to 72" of penetration for a .510" flat nose, and when penetration depth is correlating to meplat size rather than to velocity, the data supports no other conclusion. And remember, a theory is not useful if it is contradicted by empirical data.

Alf, you quoted the answer:

quote:

No they do better because the FN remains stable and does not tumble.

Comparing RH with FN, not the drag, but the stabilisation of the straight line penetration is the mystery´s solution. Gyro stabilisation is longer active.
It is boring to me, to repeat this facts over years in this forum.
Another quote:

quote:

Living tissues are solids and behave as solids.

What does it mean? 80% water tissue behave like steel? or concrete? or wood?
Nobody will confirm this. You shouldn´t stick on the ideal fluid dynamics. We have a very complex cavity generating mechanism. But if you quote:

quote:

once the projectile has passed we are left with a cavity filled with the debris of cells and structures destroyed by the crush of the passing projectile.

It is common sense, that this cavity, also forming the bubble around the bullet, is not wetting the side walls of the bullet. What you call "debris of (destroyed) cells" is in reality containing water vapour.

Alf, just a picture to add to your collection of Rhino bullet boxes. There seems to be several bullet constructions being made there as now the solids have a taped over mention "monolithic" where there used to be the drawing of the lead filled core of the "solid" bullet.



As for me being "not correct" about the drawing on the boxes, well, a picture is worth a thousand words. You must have the "old" boxes.

.

Are bullets solid or liquid?

My observation is that, with a solid bullet shaped like a truncated cone, the smaller the meplat, the less the penetration. This is a difficult one to test conclusively because, going from a true cylinder to a true cone with a progression of smaller meplats, also progressively reduces the weight. Increasing the length of the shaft to keep the weight constant, lengthens the bullet and requires the use of different rifles with tighter twist rates. It soon becomes a nightmare of variables and tumbling bullets.

One reason for decreased penetration with smaller meplats may be as explained by MacPherson. Penetration is dependent on drag. Drag is determined by the total area exposed to the direction of travel. An FN bullet with a meplat smaller than caliber will expose the tapered nose section to the direction of travel. The larger the meplat and the shorter the nose, the smaller the total area that is exposed and the less the drag. With GSC FNs, the meplat diameter and nose length is the neccessary balance between the requirement placed on the bullet during penetration and that which will produce good feeding in a properly set up bolt action.

The question has been asked a number of times here and in other threads as to how we ever managed before the new generation of FNs and monos came along. Often the question carries the implication that this new technology is a bunch of hype and that the differences between old and new are imaginary and enhanced only by commercial motives.

Take note of this thread and with specific reference to the quotes below:

quote:

The buff had a snare round it’s foot, a 9,3 bullet in it’s neck and an old .458 bullet lodged in a lung!

quote:

that buff had an RWS TUG lodged in it's neck and the .458 in one lung. We traced the bullet path through from the paunch into that lung. Both were old wounds that had healed.

quote:

All elephants taken on this exam had healed bullet wounds in the lungs.

I have seen countless times that a shot declared as a miss was actually a hit. The animal just did not react due to the fact that the bullet was not capable of following through on what the shooter started.

It is this very fact, a failure with a "premium" bullet, that was the genesis of GSC Bullets.

.

THe supercavitation effect of a flat nose solid reduces its drag, hence the deeper penetration that we see.

___

For Alf only:

The following graphical representation proves supercavitation in substances that are at least 70% water:



And here is the formula for depth of penetration when using flat nose solids (K=depth in inches):

This thread is titled:

quote:

Open questions to bullet makers

and so far as far as I can see there's not a single bullet maker posted in two pages of posts.

As far as I'm concerned I'm simply putting my money on observed results. 500 grains wins this one easily but I think we should change his name to 497 grains as anyone that goes along with this thread this long is simply several grains short of a full bullet!

quote:

Originally posted by duikerman:
This thread is titled:

quote:

Open questions to bullet makers

and so far as far as I can see there's not a single bullet maker posted in two pages of posts.

What?
Gerard makes GSC bullets.
Got it now?

quote:

What?
Gerard makes GSC bullets.
Got it now?

Yup...I was wrong as Gerard definitely makes bullets and my apology to him for my error!

Thank you, sir!

.

One more point about Robgunbuilder's concentricity theory: The 2nd most accurate group I have shot in my life was with Bridger FN solids from a 375 H&H. It was a 3 shot oblong hole at 100 yards. You had to look close to believe it was really a group.

IN SUMMARY: Make a Flat nosed CONCENTRIC bullet out of tungsten and shoot it out of a 1:15 twist .500a2. You'll LIKE THE PENETRATION RESULTS! FAILING THAT SHOOT ANY GOOD FLAT NOSE WELL STABILIZED BULLET OUT OF A 1:15 .500A2. I WOULD ALSO APPRECIATE IT IF FOLKS WHO EITHER HAVE NEVER SHOT OR OWNED OR HUNTED WITH A 500A2 WHOULD DO US ALL THE CURTESY OF NOT REPLYING. -ROB

Why 1:15 instead of 1:18?

What company makes tungsten FN solids in .510" diameter?

This is way off topic. Please do not clutter Alf's thread, PM comments if appropriate.

:

So in short, everybody agrees that FN's outpenetrate RN's, the disagreement is WHY?

quote:

Originally posted by Bent Fossdal:
So in short, everybody agrees that FN's outpenetrate RN's, the disagreement is WHY?

It may be true but it hasn't been proven to my satisfaction in all forms of living tissue and bone. I have no confidence in any tests in simulated mediums that purport to give equal results to those seen in living animals. The only test of different solid bullet shapes and construction in elephant cadavers that I know of were reported by 500grains in an article in AH magazine (Number 1 of 2005) let'a see what he says.

I quote.

Table 4 - ELEPHANT HEAD PENETRATION AVERAGES BY BULLET MAKE.

Table 4 compares penetration depth on elephant heads. Once again Barnes hemispherical RN solids_ added for clarity)penetrated the shallowest, but this time Woodleigh penetrated the deepest, with GS Custom and Bridger coming in second and third. In bone a vapor bubble will not tend to form around a bullet, which may deprive flat nose solids of some of their advantage for head shots on elephants. Nonethe less, flat nosed solids ranked second and third as far as depth of penetration on elephant heads. (End quote)

In soft tissue the only RN solid a Barnes hemispherical RN was tested in the 500 N.E. No Woodleigh RN solids were tested in this caliber. Consequently, comparative results between Woodleigh RN solids and GS or Bridgewr FN solids is not possible for the 500 N.E.
We can compare his results for all three types of solids in the 470 Capstick with 500 grain bullets. The GS Custom averaged 48", the Bridger FN averaged 72" and the Woodleigh 53". If we avearage the FNs solids we get an average of 60". Considering the small sample size I would not be comfortable in saying that this is a significant difference.

If you look at the photographs of recovered bullets in the above referenced article you will see significant nose deformation and bending of the nose of three of the five recovered GS Custom bullets and similar if not so dramatic nose deformation and bending of the Bridger FN bullets. The woodleigh bullets pictured show much less deformation and no noticeable bending. One of the 6 Woodleighs does show a minor amount of base flattening and another a small amount of lead portruding form the base. I would not be satisfied with the amount of bending and deformation dispalyed for the GS Custom bullets but the amount shown for the Bridgers and woodleighs is acceptable to me.

I appologize for not including the photos from 500grains article but or some reason my computer will not wallow me to copy and paste today.

465H&H

Well, here is some comment from people other than 500grains The page contains comment on HV, FN and our older HP bullets but the bullet commented on is clearly mentioned, so one can take note of those that are of interest for the moment. On this page see: Row one picture one, row three picture two, row four picture four, row five picture two, bottom row picture three.

We have been making FN style solids since 1997 and, given that we are one of the smalllest volume manufacturers in the business, we have a fair amount of positive feedback. In nine years, no one has contacted us with any comment of where a GSC FN bullet failed. I am prepared to stick my neck out and say if someone knows of an FN bullet that failed, please post it here so that we can determine what happened.

One caveat: Do not complain about a "failure" where the bullet was used contrary to our recommendation.

.

In my opinion there is a rather large flaw in the statement "and the vapour bubble performs most of the work of tissue disruption."

This is not logical.

The temporary cavity is formed as a result of the speed imparted to the tissue as it is displaced by the passing bullet. This displacement event has time and distance components. The distance is the diameter of the bullet and the time over which the displacement occurs is determined by the shape of the bullet that is in contact with the tissue. The larger the diameter and the shorter the time it takes to displace the tissue to that diameter, the higher the speed that is imparted to the tissue. As the speed of displacement increases so does the temporary cavity. If the size of the temporary cavity exceeds the elasticity of the tissue, tissue is disrupted and the temporary cavity contributes to the size of the permanent cavity. Simply put, if the energy of the bullet is put to work in the forming of the temporary wound channel and the energy exceeds the stored strain energy of the tissue, disruption occurs. If the stored strain energy of the tissue is greater than the energy applied by the bullet, the tissue returns to it's position. The wound channel is then caliber size or smaller, depending on the speed and the nose shape of the bullet. See the diagrams below.

Gerard,

Your drawings show crush cavity being exactly bullet diameter. But from field observation we know that the hole observed in the animal created by FN solids is much larger than bullet diameter. So there is a mechanism at work not explained by the drawings you posted.

Congratulations on the grandchild!

quote:

Originally posted by 465H&H:

quote:

Originally posted by Bent Fossdal:
So in short, everybody agrees that FN's outpenetrate RN's, the disagreement is WHY?

It may be true but it hasn't been proven to my satisfaction in all forms of living tissue and bone. I have no confidence in any tests in simulated mediums that purport to give equal results to those seen in living animals. The only test of different solid bullet shapes and construction in elephant cadavers that I know of were reported by 500grains in an article in AH magazine (Number 1 of 2005) let'a see what he says.

I quote.

Table 4 - ELEPHANT HEAD PENETRATION AVERAGES BY BULLET MAKE.

Table 4 compares penetration depth on elephant heads. Once again Barnes hemispherical RN solids_ added for clarity)penetrated the shallowest, but this time Woodleigh penetrated the deepest, with GS Custom and Bridger coming in second and third. In bone a vapor bubble will not tend to form around a bullet, which may deprive flat nose solids of some of their advantage for head shots on elephants. Nonethe less, flat nosed solids ranked second and third as far as depth of penetration on elephant heads. (End quote)

In soft tissue the only RN solid a Barnes hemispherical RN was tested in the 500 N.E. No Woodleigh RN solids were tested in this caliber. Consequently, comparative results between Woodleigh RN solids and GS or Bridgewr FN solids is not possible for the 500 N.E.
We can compare his results for all three types of solids in the 470 Capstick with 500 grain bullets. The GS Custom averaged 48", the Bridger FN averaged 72" and the Woodleigh 53". If we avearage the FNs solids we get an average of 60". Considering the small sample size I would not be comfortable in saying that this is a significant difference.

If you look at the photographs of recovered bullets in the above referenced article you will see significant nose deformation and bending of the nose of three of the five recovered GS Custom bullets and similar if not so dramatic nose deformation and bending of the Bridger FN bullets. The woodleigh bullets pictured show much less deformation and no noticeable bending. One of the 6 Woodleighs does show a minor amount of base flattening and another a small amount of lead portruding form the base. I would not be satisfied with the amount of bending and deformation dispalyed for the GS Custom bullets but the amount shown for the Bridgers and woodleighs is acceptable to me.

I appologize for not including the photos from 500grains article but or some reason my computer will not wallow me to copy and paste today.

465H&H

NOTE: On body shots, FN solids tend to penetrate 20-25% deeper than RN solids in my experience. The difference is even greater is we compare FN solids to hemispherical RN solids like the old style Barnes. On head shots there seems to be less overall difference, probably because the supercavitation bubble collapses as the bullet passes through bone.

/

Dan,
The drawings are from a talk I do and, looking at it now, I left something out. There should be a third cavity outline but, as it is so variable, I do not include it in the pictures. This third outline would delineate the wound channel when all has gone quiet. It falls between the temporary cavity outline and somewhere smaller than the crush cavity. The size of that outline is dependent on speed (or lack of it), bullet construction and the shape of the deformed bullet.

So a very slow, solid round nose often produces a smaller than caliber final outline in muscle. At the other end of the scale, a bullet with a flat meplat going fast, would produce an outline larger than caliber.

Alf, I thought everybody knew this.

Dan!

My point was that sometimes we tend to generalize our statements. The example I gave was on the data you reported on solid bullet penetration in the AH article. If we compare one caliber, 470 Capstick, and we place the various bullet types by make and nose design in order, the Bridger FN solid averaged 72", the NF Cup nose 56", the Woodleigh RN 53" and the GC Custom FN 48". With all the vagaries of bullet path, sample size variation etc., it would appear that not all FN bullets penetrated a greater amount than all RN bullets. In affect the NF cup nosed bullet is an expanding bullet and not a solid but it still came in second in the test. This is all the more perplexing to me in that in your last article on penetration of soft nosed bullets the NF Cup Nosed did not penetrate better than the Swift A-Frame or Woodleigh soft point.

Do you think that that the nose deformation and bending seen in the GS Custom bullets may be responsible for the lower penetration you saw with this bullet?

Gerard!

I have not intended to trash your product as it appears to be a very good bullet. I pointed out the differences above simply because they were there. All products can be improved and I don't think the perfect solid bullet has yet been invented. Yours are very close.

465H&H