The Steel Mistress was set up this time with entry into the first bag of water through 4 thicknesses of truck tire innertube, 2.5 mil plastic water bag with 7.5" depth of water, then one 15/32" 3-ply interior plywood board backing each bag, repeated for 12 compartments.

.470 NE North Fork .475/500gr Flat Point Solid (NF-FPS) at 2100 fps:
BOUNCED OFF THE ELEVENTH BOARD: Score 11

.375 H&H GSC .375/300gr Flat Nose Solid (GSC-FN) at 2500 fps:
BOUNCED OFF THE TENTH BOARD: Score 10

And the bigger, slower bullet did more visually, splash and board breakage.

Mo/XSA for the .470 NE is 872 lb-ft/sec.in^2.
Mo/XSA for the .375 H&H is 969 lb-ft/sec.in^2.

The .375 is supposed to out penetrate the .470.

I reckon the water and boards might get harder with higher velocity bullets.

Does this mean the .45/70 rules?

I reckon I gotta do lower velocity tests.

Penetration ranks/scores so far:

11: NF-FPS .475/500gr @ 2100 fps
10: GSC-FN .375/300gr @ 2500 fps AND 2700 fps
(a tie)
9: GSC-FN .375/270gr @ 2900 fps
8: NF-CPU .474/500gr @ 2100 fps

The latter is, of course, the North Fork Cup Point Universal, the "Cape Buffalo Soft Point," a semi-expanding bullet.

Rip,

Great work, next time out with the "Maiden" how about getting someone to get some actions shots to post. Keep up the good work. I hope the o'l gal can stand up to the 45-70-500 @ 1200 fps.

Hog Killer

Hog Killer,
I'll try to get a "splash" on camera, since Chief Thunderstick (pictured above) will be shooting his .470 Capstick next: Barnes 500 gr XLC and Smurf Round Nose solids at 2300 fps. Should be spectacular. I will try to throw in a North Fork .475/500gr FPS at 2300 fps for comparison to the the Barnes bullets, and to see if the NF-FPS penetrates less at higher velocity. If it does, I am dusting off my Marlin .45/70 and finding some hard cast lead.

The innertube is a nice touch, thanks to BigRx and you. The entry board has a diamond-shaped port cut in it and two nine inch wide bands of truck tube are stretched over the board, giving 4 layers of rubber. This keeps the water bag from bulging out, and also keeps the entry board from flying out of the contraption. The entry board gets snapped in two, but the pieces don't go anywhere. Synthetic buffalo hide.

You guys are cool. I had to shoot my 470 at a wood stump yesterday.....

Rip,

Let me know if you need any cast bullets for your 45-70 testing. I have 2 different Lyman molds, 457125/525gr RN, and 457658/490gr Spitzer. Both are made of air cooled wheel weights, if you need some very hard cast I can make you some up.

Hog Killer

RIP,

I think the NF .474 FN outpenetrates the .375 300 gr. FN because the .474 has a greater meplat, and creates a larger vapor bubble in your test medium. I was puzzled as to how my 500 NE could outpenetrate my .470 Capstick on some occasions, and the answer seems to lie in meplat size.

meplats rule! you are right on that mr.grains. thus the 45-70 debate goes on...

The ability to do work (Ke) may be a factor? The .470 bullet is just shy of 4900 ft-lb while the 300gr 375 at 2500 is at 4164 ft-lb. Meplat size is a definite factor. So we have to find a way to figure Mo/XSA, Ke, meplat size, velocity (as an indicator of stagnation pressure) and shape factor into all this to try and make sense of the results.

Some time ago we agreed that this type of testing will raise questions and anomalies that will lead to running and screaming. Are we there yet?

.

quote:

Originally posted by ALF:
500 gr:

" I think the NF .474 FN outpenetrates the .375 300 gr. FN because the .474 has a greater meplat, and creates a larger vapor bubble in your test medium "

Does the size / volume of the bubble have anything to do with penetration ?

I ask this as studies show that slimlined bubbles or cavities as propagated by slim small meplat cavitators are "better" than large meplat projectiles.

Also how do you propose cavities are maintained within the current construct of this target medium as the limted volume water volumes are interspaced with wood?

Alf,

Norbert's detailed explanations are here:

http://www.grosswildjagd.de/english1.htm

(be sure to click the sub links too)



It would seem that a larger bubble leads to deeper penetration. As the bullet hits a wood baffle in RIP's device, the cavitation bubble collapses and is re-established when the bullet exits a baffle and enters the next water bag.

nice work

confirms dave's findings
http://www.470mbogo.com/BigBores/BigBores7.html

SD, then velocity, then bullet shape, in that matrixed order, make for penetration.

300gr 375, sd .305

500 gr .475 sd .317...

and the queen mother of all SDs in a normal bolt gun
500 gr .458 bullet.. sd .341

Oh, momentum?

well, a 500 gr bullet, at 2500 fps SHOULD out penetrate the same bullet at 2380 right?

Dave's results (withing 600 lb-ft)
450 ackley 92 inches 2380 fps
470 mbogo (ave) 82 inches 2500 fos

WOW...

wait a minute...
how did a LOWER MO bullet penetrate less than a higher one?

Answer?

SD!!!

Again, proof, not formulas

jeffe

The rig is set. I will have to duplicate those results to add credibility. The GSC FN .375/300gr is the control. I've got some North .375/300gr FPS too. There may not be enough difference between the GSC and the NF meplat size to be significant, but that would be a way to isolate the meplat factor to see if it matters ...

I haven't decided what to do about the .45/70 yet, but I will ...

Hog Killer's offer is interesting, but I would like to narrow it down to one .45/70 hard cast super-penetrator load versus the .458 Lott with 500 grain NF FPS at 2200 fps.

What might that be? The best .45/70 hard cast lead penetrator?

Ron,
take some of HK's heavy bullet and turn the nose FLAT jack.. like .400 or so, and that shoudl wind up a little more than 500 gr... run it at 1500 fps... POOF a garret load

jeffe

.

I don't care why.

I'm a pragmatist and want to know, and am amply satisfied by the answers to: whether and, if so, how much?

Is a FN better and if so, how much better?

BTW, from what I've seen published so far, I don't think it's better enough to warrant replacing my Woodleighs and TB Sledgehammers with a FN.

After five feet of penetration, any more is superfluous.

RI{.

Slow down boy. Your results may be bordering on the irrelevant if you start jumping to conclusions too soon.

quote:

Originally posted by Will:
RI{.

Slow down boy. Your results may be bordering on the irrelevant if you start jumping to conclusions too soon.

Will,
No conclusions by me yet, and I am going too slow already! I have just now, after several months, settled upon the setup, and am just reporting some observations.

Let the testing begin!

And then some conclusions, maybe, or maybe not.

Have a look at the tables on this page.
Then explain to me how the Sd theory goes again.

Gerard,
Sorry to tell you this, but again you miss the point..

Good examples to demonstrate MO means ZERO in prediction of penetration
Same SD .33 same Velocity 2400fps

500 asquare, MO of 205.7, penetration of 73 inches.

416 rigby, MO of 137.1, penetration of 71.5 inches

2% difference in penetration... hmmm, ~67% difference in MO

but wait.. look at SD
differnence in SD .. .0%
difference in penetration 2%
difference in ME, ~67%


Great predictor, G.. sounds like Garrett' claim that bigger and slower penetrate better...

completely disproven by the same chart.

I'll do a point plot chart on this data later.. should be pretty clear to see which is a better PREDICTOR

LMFAO

jeffe

Will your point plot chart explain:
470 Mbogo Sd .317 = 90 boards and 470 Mbogo Sd .317 = 72 boards.
470 NE Sd .317 = 57 boards and 470 Mbogo Sd .317 = 72 boards.
458 WM Sd .341 = 66 boards and 450 Ackley Sd .341 = 92 boards.
416 Rigby Sd .330 = 71.5 boards and 470 Mbogo Sd .317 = 72 boards

quote:

Originally posted by Gerard:
Will your point plot chart explain:
470 Mbogo Sd .317 = 90 boards and 470 Mbogo Sd .317 = 72 boards.
470 NE Sd .317 = 57 boards and 470 Mbogo Sd .317 = 72 boards.
458 WM Sd .341 = 66 boards and 450 Ackley Sd .341 = 92 boards.
416 Rigby Sd .330 = 71.5 boards and 470 Mbogo Sd .317 = 72 boards

Gerard,
Perhaps if you READ my initial post on the subject, you would have your answer... Since I don't want you to have to scroll back, here's the quote

quote:

Originally posted by jeffeosso:
nice work

SD, then velocity, then bullet shape, in that matrixed order, make for penetration.
Answer?

SD!!!

Again, proof, not formulas

jeffe

So, can you again explain how MO can vary so wildly in penetration results?

Now, go ahead and behave poorly, rather than address points.. I'll sort the chart based off 1: linear progression of SD
and
2: Linear progrssion of MO..

and then you can tell us all which is a smoother predictor...

linear, sir...

You make a good product, and it's not snake oil, so don't try to sell it like that.

Jeffe

BTW
Gerard, it's inches, not boards. Please review the facts, rather than your memory of them, okay? Or, if "slipping" units means "nothing" then I understand how you believe MO has something to do with it

jeffe

BTW Who said Mo is a good predictor of penetration when comparing different calibres?

You are right it is inches of wood and air. It remains as units for comparison. Does that change anything relevant to this discussion?

Having a background in statistical researech and sample testing, I get concerned when we try to make definative statements on comparisons of depth of penetration with sample sizes of one. How do we know that the next test might show opposite results especialy when we are looking at one board differences? To have a meaningful comparison we need multiple trials and we need to compute the variance of those estimates. Then test whether there are statisticaly significant differences in the results.

465H&H

Rip,

Keep up your efforts, inspite of the pi$$ing patch that some want to create around it.

If theories do not meet up with real world test results then guys, guess which is wrong. For those who think that single samples are not enough to prove a point, build your own trap and post your results here.

I will step off od my soap box now.

Hog Killer

Rip: I've seen your posts of the steel mistress on another site (I think)... Great project!

Penetration is a curious thing. A comment on the grosswildjagd cavitation article: the continuous production of the cavity is supported by the transfer of energy to the fluid; it must take more energy to make a bigger cavity move through the fluid. At the least, the rate of fluid encounted by the bullet is rougly density *v*A (v = velocity, A = area of bullet -- could/should be of cavity), and the momentum being transferred per unit time is proportional to the velocity imparted times the rate the mass is displaced, transferring momentum density * A *v^2 (I believe this argument goes back to Newton; drag functions for air show how much more complicated this can be -- add gristle and bone, and you're on another planet as far as complexity is concerned). The rate (power) of energy transfer is force times velocity, which must be proportional to A*density*v^3 ! I won't dig further into that.

However, RIP, you might love to see someone else's version of a "steel mistress," which he called his "elephant sandwich." He included soaked telephone books and elephant bones in with his boards. Some of the pictures of projectiles are the same as those that showed up in the grosswildjagd page.

http://www.african-hunter.com/solids_vs__mono.htm

Enjoy!

Dan

Sorry Keith, i too respect what Rip has done... but Gerard's insistance that MO is anything but an artifact is like a fly in a nice cool glass of beer.

quote:

Originally posted by Gerard:
BTW Who said Mo is a good predictor of penetration when comparing different calibres?

You, Gerard, sorry...

well, then i guess you won't argue MO is a "good" comprator for the same caliber?

Funny...
mo 153.6, 57", mo 178.6, 72", mo 178.6, 90inchs (not a typo on the last two, both 178.6"

while a .017 SMALLER bullet, with a LOWER mo (171.4) went 92 inches...

WOW.. what changed?

Bullet construction, SD in the latter, and velocity.

In fact, the 72" and 90" are from the SAME caliber, at the SAME speed...

a 25% increase in penetration from the SAME mo.. same velocity, and same energy? Hmm, bullet construction

So, these little tests prove a couple things
1: MO has nothing to do with comparing penetration, period
2: ME has nothing to do with comparing penetration, period

Which leaves little factors like SD, Construction, and velocity.

oh well, gerard, I reckon "damn, he's right" isn't in your vocabulary, especially when facts from YOUR OWN web site, without refering to the actual author of the material (that's just a little cheesy), prove these facts for you.


jeffe


As anyone can see, there's no trending to MO to Inches even when following, while the SD to Inches, with the odd exception of the 92" of the woodleigh 470, track along nicely

quote:

Originally posted by DanEP:
Rip: I've seen your posts of the steel mistress on another site (I think)... Great project!

Dan

Dan,
It must have been linked by someone else, not me, IF it was seen anywhere other than this site.

I cannot afford to get into scientific interpretations right now, as my mental capital is too small, and besides we have beat around this bush so many times before ...

I'll just keep collecting data until some significance accumulates. That might include some Garrett .458/540 grainers at 1550 fps out of a Ballard rifled Marlin .45/70.

quote:

Originally posted by RIP:

That might include some Garrett .458/540 grainers at 1550 fps out of a Ballard rifled Marlin .45/70.

RIP,

I am really curious to see how straight those 500gr and up and the heavy pointed .45-70's do in the "Steel Mistress" with their 1 in 20" twist! Be sure and let us know whether the plywood has a hole or a keyhole...........

BigRx

BigRx,
Thanks for the innertube idea. Slow twist and long bullet is an interesting consideration.

In the Steel Mistress, the pattern with the FN's, FP's and CPU has been straight penetration with round hole in board until the next to last board penetrated. For example: 8 boards with round holes, 9th board with slightly oval witness hole, 10th board with obvious keyhole, almost completely sideways penetration, then 11th board a dead stop.

Once the bullet goes through a board sideways, the next bag of water will stop it and contain it, even if it smacks sideways into the last board in the train.

The boards are for witness of this inevitable keyholing as the bullet loses forward velocity and spin in the wood and water.

The boards also add good resistance of a different sort from the water, but more resistance comes from water than from wood in the SM.
It will be interesting.

Jeffe,
You are arguing for the sake of arguing. Your elaborate difference of opinion is based on several wrong assumptions. I have not said that Mo is an indicator of penetration across calibres and I have not said that Mo is an indicator across bullet construction types, do not pretend that I did. This thread has been informative until you entered with your demeaning and insulting style of pontificating. "Now, go ahead and behave poorly, rather than address points." You should heed your own words.

Your charts are based on very strange logic. How can you say that sorting by Sd proves a link to penetration? The truth is revealed when you sort by penetration and observe if Sd follows the trend. Does it?

Ron,
sorry to have hijacked your thread. I've posted a couple facts that match with your facts, and will shutup with this BS with gerry after this post

Gerard,
At least you are predictable and consistant.. even that means you insult and demean anyone who disagrees with you, as your first response,
gerard's first reply to me EVER

and then present a strawman arguement, and the go right to perposterous...Recall, Gerry, that the FIRST time I had the "nerve" to questions the "mighty gs custom bullet maker" who is a plagerist, you insulted me, posted insulting pictures, and told me to kiss your arse.

Who said MO was an indicator across calibers? Well, Gerry, YOU did, do, have on many occasions, and refuse to discuss that SD has any indictor of penetration.

https://forums.accuratereloading.com/eve/forums/a/tpc/f/2.../844100542#844100542

SD is a fact, MO is an artifact....

So, gerard, give it up.. your own facts and posts contradict you

jeffe

RIP;
Keep up your very interesting work, even if it not reaches statistic relevance at the moment.

But guys, when citing the Grosswildjagd page, pls. read it carefully. It may be caused by my limited english that again I see a lot of misunderstanding here.

DanEP:
"The continuous production of the cavity is supported by the transfer of energy to the fluid; it must take more energy to make a bigger cavity move through the fluid."

Right. And the bigger meplat decreases the ability to penetrate the medium if only drag is responsible.. But this ability is not used by RN solids because they tumble and veer off before reaching their maximum penetration depth. The diameter of the meplat of my SuperPenetrator is a compromise, also taking into account the size of the wound channel.

Alf:
" " I think the NF .474 FN outpenetrates the .375 300 gr. FN because the .474 has a greater meplat, and creates a larger vapor bubble in your test medium "

Does the size / volume of the bubble have anything to do with penetration ?."

Yes. A greater bubble gives more room for restabilisation when the bullet is tumbling a bit, especially when the bubble is reestablished in the subsequent compartments of RIP´s setup.

"I ask this as studies show that slimlined bubbles or cavities as propagated by slim small meplat cavitators are "better" than large meplat projectiles.When looking at supercavitating projectile motion in a pure fluid there is ample evidence that slimline cavities with the smallest diameter cavitators produce the least amount of drag and therefore penetrate the best."

Here you are referring to arrow/fin stabilised under water projectiles where the cavitation is only used for reducing the drag caused by friction at the hull. In this application a stabilisation by cavitation is not needed.

"By this analogy alone a small meplat cavitator alone combined with a slim cavity would outpenetrate a big meplat "big bubble" scenario."

Right, if you can maintain the straight line stability of the bullet´s path.

"As to the theory of supercavities being evoked in Elpehant skulls...."

Why do you insistent coming with this BS. I never made such a statement. I only presented the excellent results on elephants. May be there is some cavitation through the trunk and in the neck region. But that is off topic here.

Gerard is fighting for his "light bullets" philosophy as other manufacturers of copper bullets. But why ignoring SD?

.

Gentlemen,

I think we have to be careful not to expect that a bullet will perform the same in game as it does in a penetration test. For example, Dave's test of shooting dry wood boards showed that SD is a very significant factor influencing penetration. But does that mean SD will be equally as important in a bullet penetrating game animals (which are about 80% water content)?

Jeffe,
You are a liar.
Lie#1: You have consistently started the string of insults. Claiming that I did is a lie. Do not complain if you get what you dish out.
Lie#2: Your reference to the seven page thread as evidence that I hold momentum as an indicator of penetration across calibres or differing bullet types is a lie. It was you who said: "Please review the facts, rather than your memory of them, okay?" Again, heed your own advice.
Lie#3: Stating that my own posts and facts are contradictory is a lie. You cannot come up with a single example if you tried.
Lie#4: Calling me a plagiarist is a lie. I did not claim the work you refer to as my own. Check the opening line of the page. The tables were sent to me by a customer and is assumed to be in the public domain.

You also said: "Now, go ahead and behave poorly, rather than address points." So when you have no answer to the penetration/Sd chart I showed, you go ahead and behave poorly. This is par for the course with you, a habit.

You have again confirmed my opinion of you which I have expressed before: There are many whose opinions I respect and many whose advice I would heed, you are not amongst them. You are a small minded and spiteful individual and your behaviour is no better than a common troll. Your "status" as a moderator is a joke.

Alf:

BS is to ignore my statements on the two mechanism on stabilisation of bullets in game .
In aqueous media (tissue) it is what I call supercavitation.
In bone, sinew etc. it is a very different mechanism caused by forces on the shank. I never said that in ele skulls or bone supercavitation occurs.
You wrote:
"If you contend cavitation only as mode of function yes, then I can accept your proposals but if you contend "supercavitation" as the model then I find no common ground. and:
"Cavitation yes as this underlies the principles of terminal ballistics, supercavities no !"

I don´t know what my old professor in physics would say, but modern terminology uses supercavitation for the embedding of a projectile in a gas bubble, even when generated by injection of additional gas. The term cavitation is used for a minor effect of generating small isolated bubbles.
But where is the problem if we are discussing only terminology and not technical important matter?

Therefore : "where you claim your product adheres to the principle of Supercavitation. You even have an animation picture of your bullet in it's supercavity bubble !"... my statements are fully confirmed, you may for your satisfaction replace the term supercavitation by an expression you like.

RIP -- did you get a chance to look at the elephant sandwich link in my prior post? Looks like a kindred spirit!

Dan