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Just three short answers:

1. You are mistaken with what a temporary cavitation is in terms of what you see. When bone is encountered one sees a splintered effect and when a water-filled gut is encountered it will rapture. Alf has explained this numerous times and cautioned that we non medical people make sometimes wrong deductions.

2. Regarding the silly question of Ratmotor that you bring up. If he read my earlier post about velocity windows at which we normally shoot certain cartridges, he would have understood that his question is off the wall. It follows then you are in the same position, as you believe the question must have some value.

3. The analogy of the ball and the bullet stands. It is amazing how you can mix things up. SD is at work if we like it or not - it is that simple. Alf also said so ad nauseum. That means you also have learned nothing in this thread.

Warrior
 
Posts: 2273 | Location: South of the Zambezi | Registered: 31 January 2007Reply With Quote
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quote:
1. You are mistaken with what a temporary cavitation is in terms of what you see.


So this squirrel did not really disappear in a red haze, we are imagining it.



And these bones were actually broken by magic.



quote:
2. Regarding the silly question of Ratmotor that you bring up. If he read my earlier post about velocity windows at which we normally shoot certain cartridges,
How come you are the only one allowed to apply velocity windows? Your selective choosing of circumstances to suit your (and only your) point of view would have been funny if it were not for the fact that you seem serious about it.

quote:
3. The analogy of the ball and the bullet stands.
It stands as a monument to the fact that you flip flop between Sd as the driver of penetration and momentum/area as the driver, as it suits your particular peculiar argument of the moment.

What say you to:
----------------------------------------
1. quote:
I do not like petals that fly off within the first inch or two.

Who cares what you like, as long as it works. But, as a matter of interest, why would you say petals come off in the first inch or two? Under what conditions would this happen and to what kind of bullet?
-----------------------------------------

2. quote:
Your concluding paragraph basically ridicules the importance of SD ...

I see. The tongue in cheeck tone of the entire article escaped you. There is nothing new about that, there is so much that you miss. Am I right in assuming that you find no technical fault with the article. No lies, mistakes or wrong facts that could lead a newby down the wrong road?
------------------------------------------

3. You claim Alf said:

quote:
Therefore if we shoot two expanding projectiles of equal construction ( thus similar yield strength) one heavy and one light, both at equal impact velocity, both will be subjected to the same tip force and thus will expand equally.

When did Alf say this?
------------------------------------------

4. Are you saying that MacPherson is wrong?
------------------------------------------

Or are you going to ignore those questions because answering them will prove you were wrong in every case?
 
Posts: 2848 | Registered: 12 August 2002Reply With Quote
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Gerard,

Momentum (the product of mass and velocity) is a very useful factor, but as an absolute figure it does not tell us much if it is shapeless or when we have no idea of form (caliber, ball or bullet). Furthermore, we can have a high momentum value at very low speed and low momentum at high speed that changes the character of the force noticeably at the extreme ends - that is why velocity windows are for real and must be recognized. That means we just cannot ad infinitum replace mass with velocity to make up the same momentum values, as the bullet can only withstand so much velocity before is blows to pieces. In-target drag also goes up to the square of velocity, and so will influence depth of penetration. So, "velocity windows" are not a ploy that I use when it suits me, it is there because it is a fact. Both mass and SD are properties of a bullet and the one cannot live without the other. Mass does not tell us the form or shape - mass could be penny-like, ball-like or bullet-like, whereas SD gives it "form" in terms of mass behind the frontal area (Xsa). SD only comes alive when it is put into motion.

Alf has mentioned over time the various important contributions of ballisticians that wrote reference works, filled with all kinds of mathematical equations including the military. Here is one of Alf's comments ... "What is more amazing is that I have been reading stuff on the tests done by NASA on the impact damage to the Space Shuttle and even they with all their knowledge also refer to this non entity (SD)?" Then there is Sellier and Kneubuehl that points out the importance of SD to every branch of ballistics theory. Are all these people wrong? I do not say MacPherson is wrong, we need to make sure that we interpret him correctly and not out of context, as you have done before when Alf pointed that out to you. My submission was that bullet construction can limit expansion by design - for example, and I will give a very simple explanation ... If we drill a hole of 2 mm, or 3 mm, or 4 mm, ....... all the way up to 10 mm a Barnes-X bullet , we will have very different expansion, as it rolls up to maximum within its velocity window. If we do not drill a hole in it, it remains a solid and do not mushroom. It is done by the force or momentum behind the tip of the bullet and not because of SD per se - SD is not a force, it is a ratio without motion. Only when velocity is applied will we get momentum and deformation will go up as we apply more velocity that drives momentum values up.

The diminutive 7x57 mm kills Kudu astonishingly well with 175 gr bullets at modest velocity, to the surprise of 30-06 fans, and bullet penetration is always good with CEB's despite double expansion of diameter. This combo of a .310 SD premium construction bullet blends in very well with the normal velocities that we use the caliber in as it does not destroy the bullet and so it performs above expectation for those magnum freaks. I doubt if a blunt cylinder will serve me better.

On this note I wish you a happy Xmas and prosperous new year, as I am off with vacation to Mauritius on Monday.

Warrior
 
Posts: 2273 | Location: South of the Zambezi | Registered: 31 January 2007Reply With Quote
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All that waffle, repeating the same old stuff, laying of the smokescreen and not a word about:

quote:
What say you to:
----------------------------------------
1. quote:
I do not like petals that fly off within the first inch or two.

Who cares what you like, as long as it works. But, as a matter of interest, why would you say petals come off in the first inch or two? Under what conditions would this happen and to what kind of bullet?
-----------------------------------------

2. quote:
Your concluding paragraph basically ridicules the importance of SD ...

I see. The tongue in cheeck tone of the entire article escaped you. There is nothing new about that, there is so much that you miss. Am I right in assuming that you find no technical fault with the article. No lies, mistakes or wrong facts that could lead a newby down the wrong road?
------------------------------------------

3. You claim Alf said:

quote:
Therefore if we shoot two expanding projectiles of equal construction ( thus similar yield strength) one heavy and one light, both at equal impact velocity, both will be subjected to the same tip force and thus will expand equally.

When did Alf say this?
------------------------------------------

4. Are you saying that MacPherson is wrong?




It seems that I was right when I said: "Or are you going to ignore those questions because answering them will prove you were wrong in every case?"
 
Posts: 2848 | Registered: 12 August 2002Reply With Quote
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Hey G,
I am not certain WHY warrior is being intentionally an ass, but I am certain he IS doing it intentionally.

You and I don't always see eye to eye, but, then again, that's why there's horse races.

it is really as simple as the Berry-Smith SD ..
.275 for copper based monometals ...
or restated, determine the LENGTH of the desired SD bullet of conventional design, and turn that shape and length in a mono metal bullet. Performance will be pretty much the same.

For example, only a fool would argue that a 450gr barnes .458 X or TSX bullet penetrates LESS than a 450gr conventional expanding bullet, at the same speed.

jeffe


opinions vary band of bubbas and STC hunting Club

Information on Ammoguide about
the416AR, 458AR, 470AR, 500AR
What is an AR round? Case Drawings 416-458-470AR and 500AR.
476AR,
http://www.weaponsmith.com
 
Posts: 39823 | Location: Conroe, TX | Registered: 01 June 2002Reply With Quote
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Jeffe,
Agreed.

Regarding Chris, I think you are wrong. He is not an ass, he is a dumbass. I love it when he paints himself into a corner and then refuses to admit it.

thumb
 
Posts: 2848 | Registered: 12 August 2002Reply With Quote
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Jeffe,

When SD was debated way back in March 2005, you opposed Gerard on the issue of SD being irrelevant.
You then defended SD, but it seems you have now changed your mind ? If not, then please state so.
Perhaps you could get us all singing from the same hymn-sheet.
Please just be civil and not like Gerard.

Just to remind you how Gerard addressed you in his post on March 2005 (07:57) and I quote ... "You really are stupid and have trouble reading and comprehending or you are a coward and you cut and run with that inane reply. Either way suits me but it would have been nice to whip your sorry butt." Multiple insults in just 2 sentences. Jeffe, you see Gerard's style is to make personal derogatory remarks when in a conflict situation, and that has not changed since then. In fact you may have noticed that in every post he makes derogatory remarks about me as if it would elevate him.

Anyway, no further post from me on this issue.

Warrior
 
Posts: 2273 | Location: South of the Zambezi | Registered: 31 January 2007Reply With Quote
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Warrior,
You disappoint again. As always.

Most of us here are open minded enough to learn and change our opinions through the exchange of observations and ideas between self and others.

Not you. You old dog! You are all "self." You are stuck in the past, floating in your personal sewer. Flush yourself!

You need to shoo-thataway Wink until you grow up and learn to adjust your opinions of other people and "things" as any intelligent person must do.

Adapt or go away. Darwin calls you.
 
Posts: 28032 | Location: KY | Registered: 09 December 2001Reply With Quote
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Warrior- Thankl God no more posts from you on this topic. The stream of bullshit finally ends. Oh well it was laughable and brought tears to my eyes. -Rob


Never underestimate the power of stupid people in large numbers to do incredibly stupid things- AH (1941)- Harry Reid (aka Smeagle) 2012
Nothing Up my sleeves but never without a plan and never ever without a surprise!
 
Posts: 6314 | Location: Las Vegas,NV | Registered: 10 January 2001Reply With Quote
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quote:
Originally posted by Warrior:
Jeffe,
...You then defended SD, but it seems you have now changed your mind ? If not, then please state so.
Perhaps you could get us all singing from the same hymn-sheet.
Please just be civil and not like Gerard.
..Anyway, no further post from me on this issue.

Warrior


Chris,
YOu are taking this out of context. G's position was that SD was not important, mine POV is that it is. Today, with time for repose, I still feel SD is critical, but the number for copper based bullets is .275+ rather than .300+

that he and I exchanged insults is between the two of us.

Is this clear enough for you?

Though I doubt this is your last post, but that would be nice to think it could be


opinions vary band of bubbas and STC hunting Club

Information on Ammoguide about
the416AR, 458AR, 470AR, 500AR
What is an AR round? Case Drawings 416-458-470AR and 500AR.
476AR,
http://www.weaponsmith.com
 
Posts: 39823 | Location: Conroe, TX | Registered: 01 June 2002Reply With Quote
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I think I have found a way to nudge Truvellowarrior into honouring his promise not to post on this thread any further. We know he will need some incentive so, here it is and I have drawn the parameters a bit wider. I have placed a bet with four of our staff and two customers, that he will be back here with some more strange theories before the 15th of January. "Here" excludes the Political Forum but includes any post on AR in which he mentions Sd or penetration or quotes from any source in that regard, as well as any post on this thread, regardless of what he says. If he posts within that time frame and context, I will make some money. If he does not, it will cost me money.

If I make a couple of bucks, that will be good, if I lose, it will be money well spent.
hillbilly
 
Posts: 2848 | Registered: 12 August 2002Reply With Quote
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quote:
Originally posted by Gerard:
Recovered bullets by max diameter and description of remains:
1600 fps: .659" = 167%, expanded down two-thirds of hollowpoint, symetrically, with 3 petals partially folded back.
2500 fps: .768" = 194%, broke off 2 of 3 petals, petals found in third bucket with bullet, one petal still attached.
2725 fps: .554" = 140%, blew off nose and left a widened, nose-heavy penetrator, one loose petal found on ground beside bucket train.



Gerard,
Here is another picture of those bullets (.395/340-grain HV), since I do not know if you saw this on the other thread with the initial scan pictures:



The one petal I found from the 2725 fps bullet must have stayed inside one of the buckets and got leaked or poured out with the dirty pond water.

I will be more careful in the future to ascertain the location where the petals come to rest.

That 2500 fps bullet lost 2 petals and hung onto the third to the end of the third 5-gallon bucket. Every bit of that 340-grains of copper was found in the third bucket it would seem. It did not shed the petals untill after it had passed through 14.5"x2 of water, 3 bucket lids and two bucket bottoms, and somewhere in the third 14.5" of water the petals came off and the bullet hit the bottom of the third bucket hard enough to dent/mark the plastic.

If Warrior shuts up a bit, maybe you can make a few more .395/340-grain HV's, SP's, and FN's? Big Grin

Don't answer here, please.
Send me a PM or email, please.
 
Posts: 28032 | Location: KY | Registered: 09 December 2001Reply With Quote
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quote:
I still feel SD is critical, but the number for copper based bullets is .275+ rather than .300+


Agreed, and thanks for not abandoning SD entirely to the point that it is totally irrelevant as some claim. That makes at least 3 of us that still see some value (not absolute value) in SD - you, me and Alf. Sd needs to be used in its proper context and not stupidly.

thumb thumb thumb

Best wishes for 2008.

Warrior
 
Posts: 2273 | Location: South of the Zambezi | Registered: 31 January 2007Reply With Quote
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quote:
Agreed, and thanks for not abandoning SD entirely to the point that it is totally irrelevant as some claim.


Chris,
Stop hinting at who this mysterious person is who is claiming that Sd is completely irrelevant. Tell us who it is (hint, hint, nudge, nudge).

PS. Thanks for the small New Years bonus, I will put it to good use.
thumb
 
Posts: 2848 | Registered: 12 August 2002Reply With Quote
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quote:
Originally posted by Warrior:
Jeffe,
....Anyway, no further post from me on this issue.

Warrior


a lie?

quote:
Originally posted by Warrior:
quote:
I still feel SD is critical, but the number for copper based bullets is .275+ rather than .300+


...that makes at least 3 of us that still see some value (not absolute value) in SD - you, me and Alf. Sd needs to be used in its proper context and not stupidly.

Warrior


No chris, he is quoting the berry-smith formula update on SD...

Please ACTUALLY read what is written


opinions vary band of bubbas and STC hunting Club

Information on Ammoguide about
the416AR, 458AR, 470AR, 500AR
What is an AR round? Case Drawings 416-458-470AR and 500AR.
476AR,
http://www.weaponsmith.com
 
Posts: 39823 | Location: Conroe, TX | Registered: 01 June 2002Reply With Quote
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Jeffe,
quote:
Please ACTUALLY read what is written

You expect too much, he does not even read what he writes himself. The latest gem:
quote:
Shooting into steel is very different to shooting into steel. I guess it takes some experience to discover this.
Then there is this one, which he first wrote in January 2005 and repeated verbatim on the 25th of last month, proving that he relies mostly on cut and paste, coherent or not:
quote:
Penetration was shallow because of over expansion and the two gemsbok had to take multiple shots each, except for the warthog.
But the best one of all must remain:
quote:
Pieter Olivier an I have shots may Impala bullets


clap
 
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This was a long one. Doug left after the first page. As to Warrior and Alf, where is Ollie when you need him. Packy
 
Posts: 2140 | Registered: 28 May 2002Reply With Quote
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Jeffe,

I am not going to debate SD any further, so there is no lie. There is also no point to do so. All that wanted to express their views have given their comments already, save for some that prefered to make snide remarks rather than contributions. I have just agreed with you and wished you a happy new year - that was all. If you say SD is critical then it it good enough for me. I take it that "critical" actually means that SD is a factor. In closing, I have agreed with you; I did not debate the issue any further.

Gerard,

As for your comments about inadvertant typos, no comments from me. Go on nit-picking. It is not even related to the topic at hand. Incessant efforts to ridicule one's opponent is not the way to tackle an issue. This is not the way to persuade or to win people over. It is mush better to stay with the debate, put your view forward rather than heavy reliance on caricature to try to sustain one's position.

Happy new year to all.

Warrior
 
Posts: 2273 | Location: South of the Zambezi | Registered: 31 January 2007Reply With Quote
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quote:
Warrior Posted 09 December 2007
Anyway, no further post from me on this issue.

quote:
Warrior Posted 31 December 2007
Sd needs to be used in its proper context and not stupidly.
Warrior

quote:
Warrior Posted 01 January
I am not going to debate SD any further
Warrior


jumping
 
Posts: 218 | Location: South Africa | Registered: 26 January 2005Reply With Quote
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Hi Rat Motor,

Happy new year to you and best wishes.

Take care,
Warrior
 
Posts: 2273 | Location: South of the Zambezi | Registered: 31 January 2007Reply With Quote
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Chris/Warrior/Truvelloshooter
quote:
Please just be civil and not like Gerard.


Your posts in this thread prompted the following comments from other members. Not one of the comments below came from me, although I agree with them all and applaud the eloquence of some, many are more insulting than anything I have ever called you.

Why is it that you only complain when I call you on your mistakes and lack of understanding?

Your agenda of targeting GSC is too transparent and has become boring in the extreme.

Read the comments below and realise that there are more members here who are tired of your bickering over nothing. Take the hint man.


1. sigh.. this is confusing several disciplines again.

2. your momentum figure for a 175gr bullet going at 2390fps should be 59.8 not 68.75.

3. If this is supposed to prove that speed cannot replace sectional density your reasoning is flawed.

4. DUH! and this has NOTHING to do with the BS Formula, as it references SOLIDS.

5. Don't mix metaphors!

6. Give him hell

7. he is getting confused about nonexpanding solids versus expanding softs.

8. like old dogs that cannot be taught new tricks. Warrior is like an old dog too.

9. Your samples are at three different speeds you moron.

10. It looks like this thread is even further over your head than the sexual destiny thread.

11. I have not read such a load of nonsense in years.

12. Methinks tis time to bow out take me toys and begone

13. I understand how exasperating Warrior's last post was to you. Do not let it drive you away. He needs more help.

14. the bullshit is rolling along.

15. You are comparing apples with oranges.

16. Your example of Barnes bullets is poor on two counts.

17. and thats a fact which does not sit well with your example.

18. Yep, he is hopeless. My condolences to all affected parties.

19. Translation: Duh.....I dont understand......dont want to be confused with facts.......duh......what happened?

20. I think we have just witnessed a five way Cluster F---K of near biblical proportions!

21. You are way out of your league.

22. you sure as hell can't be serious.

23. pay attention though, not everybody here is stupid.

24. Good job on Bozo!

25. Hysterical new level of Bullshit has evolved lately.

26. I am not certain WHY warrior is being intentionally an ass, but I am certain he IS doing it intentionally.

27. You disappoint again. As always.

28. You are stuck in the past, floating in your personal sewer. Flush yourself!

29. until you grow up and learn to adjust your opinions of other people and "things" as any intelligent person must do.

30. Adapt or go away. Darwin calls you.

31. The stream of bullshit finally ends. Oh well it was laughable and brought tears to my eyes.

32. Though I doubt this is your last post, but that would be nice to think it could be

33. a lie?

34. Please ACTUALLY read what is written


PS
Why are you ignoring the question below? Scared you will be called on another lie/mistake/? You do like to posture and strut ander false pretexts of your own making, don't you.

Chris,
Stop hinting at who this mysterious person is who is claiming that Sd is completely irrelevant. Tell us who it is (hint, hint, nudge, nudge).
 
Posts: 2848 | Registered: 12 August 2002Reply With Quote
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quote:
Originally posted by jeffeosso:
..No chris, he is quoting the berry-smith formula update on SD...

Please ACTUALLY read what is written


I don't believe my little joke of the formula name went unnoticed!!!

joke in the name or not, I am deadly serious, the SD target for copper based monometal solids is .275+ ..

SD is important, you gectha.. but actually HITTING the target is critical LOL


opinions vary band of bubbas and STC hunting Club

Information on Ammoguide about
the416AR, 458AR, 470AR, 500AR
What is an AR round? Case Drawings 416-458-470AR and 500AR.
476AR,
http://www.weaponsmith.com
 
Posts: 39823 | Location: Conroe, TX | Registered: 01 June 2002Reply With Quote
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Nice Pictures
 
Posts: 2209 | Location: Delaware | Registered: 20 December 2002Reply With Quote
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"In bullets of the SAME velocity, the HEAVIER bullet will penetrate DEEPER if ALL other things being EQUAL."

Dr. Robert A. Rinker.
Naval Gun Researcher Designer and Builder.
In "Understanding Firearms Ballistics".



Mannlicher7.
 
Posts: 14 | Registered: 14 December 2007Reply With Quote
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quote:
Originally posted by Macifej:
Jeffe!

This is the AR Big Bore Forum! We can have 5 states of matter here can't we??!?

1) Gas - the most common state of matter here at AR!

2) Liquid - what some of AR consume too much!

3) Solid - state of cranial matter for some of us. IE - concrete, rock, potato, etc.

4) Plasma - the equivalent state of most of the theories proposed on AR.

5) Elastin - the state of said theories after they are debunked in the plasma phase.


Where's Rat Motor been lately ...?? Did he throw a rod and go to the big junkyard in the sky ...?? Big Grin
 
Posts: 13301 | Location: On the Couch with West Coast Cool | Registered: 20 June 2007Reply With Quote
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Only the Shadow knows. space


VVarrior
 
Posts: 127 | Location: South of the Zambezi 2 | Registered: 22 March 2008Reply With Quote
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Well VVarrior ... what pray tell is happening South of the Zambezi this fine day ...?? Wink
 
Posts: 13301 | Location: On the Couch with West Coast Cool | Registered: 20 June 2007Reply With Quote
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quote:
Originally posted by Mannlicher7:
"In bullets of the SAME velocity, the HEAVIER bullet will penetrate DEEPER if ALL other things being EQUAL."

Dr. Robert A. Rinker.
Naval Gun Researcher Designer and Builder.
In "Understanding Firearms Ballistics".



Mannlicher7.



This is like saying the sun rises in the east, sets in the west, and that the earth has a spherical shape, not flat, and it is spinning counterclockwise when viewed from above its north pole, and is spinning clockwise when viewed from above the south pole.
Or is it?

This assumes the greater sectional density of the heavier bullet does not cause the nose to deform more than that of the lighter bullet at same velocity.

We all think that sectional density drives penetration.
Sectional density also drives expansion. Duncan MacPherson.

However, with a copper or even brass FN solid at high enough velocity, there may come a point where the nose expansion of the heavier bullet exceeds that of the lighter bullet, and the drag increase negates the greater momentum of the heavier bullet ... and the earth wobbles.
 
Posts: 28032 | Location: KY | Registered: 09 December 2001Reply With Quote
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SD is a factor (a figure of merit) in the northern hemisphere, whist in the southern hemisphere it is just a practical joke by someone with a macabre sense of humour. I have this on authority. Wink

Does the discrimination between 150 gr, 165 gr, 180 gr and 200 gr bullets in .300 cal have anything to do with SD?

Warrior
 
Posts: 2273 | Location: South of the Zambezi | Registered: 31 January 2007Reply With Quote
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Warrior - next time you see Alf out at the Hippo pond ask him why he deletes his posts on these threads ...??? rotflmo
 
Posts: 13301 | Location: On the Couch with West Coast Cool | Registered: 20 June 2007Reply With Quote
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?
 
Posts: 7857 | Registered: 16 August 2000Reply With Quote
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quote:
Originally posted by ALF:
What makes you think I hang out at the hippo pond ? Why not ask me yourself ? You know where to find me !


Ok ...the Croc pond ... Big Grin
 
Posts: 13301 | Location: On the Couch with West Coast Cool | Registered: 20 June 2007Reply With Quote
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Holy smoke!
And I thought I was bored before I started reading this thread.......!
My only comfort is that some of you guys has to be even more bored than me, to be willing to answer all this crap.

But - oh, hell.

The reason that SD alone does not give an answer to penetration is very simple.

It was never intended to do so.


Bent Fossdal
Reiso
5685 Uggdal
Norway

 
Posts: 1707 | Location: Norway | Registered: 21 April 2005Reply With Quote
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quote:
Originally posted by Bent Fossdal:
Holy smoke!
And I thought I was bored before I started reading this thread.......!
My only comfort is that some of you guys has to be even more bored than me, to be willing to answer all this crap.

But - oh, hell.

The reason that SD alone does not give an answer to penetration is very simple.

It was never intended to do so.


Another product of the Southern African Compulsive Debate Club ... AR is littered with these "discussions" where pre-eminent Club members discuss the finer points of ballistic etiquitte ... be glad you're positioned in the furthest lattitudes of an opposite hemisphere as their affliction is sometimes contagious ... Big Grin
 
Posts: 13301 | Location: On the Couch with West Coast Cool | Registered: 20 June 2007Reply With Quote
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?
 
Posts: 7857 | Registered: 16 August 2000Reply With Quote
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Hey it was Man7 that brought it back from the dead - I was just spicing it up a bit. You have an honorary membership program fur far-ners do ya ...??

Cool
 
Posts: 13301 | Location: On the Couch with West Coast Cool | Registered: 20 June 2007Reply With Quote
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Dragging this thread back from the crypt served one useful purpose. It made me aware of something I should have pointed out at the time.

The statement was made:
quote:
Two expanding bullets of the same construction, but one heavier than the other, fired at the same speeds, will result in the heavier bullet expanding more.


Pontificus Erroneus disagreed with this very strongly and to the extent that he demanded that a test be done to prove that he is right. If such a test proved him wrong, he said that he would be prepared to accept that he is a moron. His exact words were:
quote:
I was called a moron because Ratmotor pointed out that the bullets must be shot at the very same velocity and not at differing velocity, as IF it would change the outcome... I have not changed my stance on this issue. I proposed that we shoot Swift A-Frame bullets in a 30-06 Spr as follows:

a) Shoot a 150 gr bullet at say 2,500 fps
b) Shoot a 180 gr bullet at say 2,500 fps
b) Shoot a 200 gr bullet at say 2,500 fps

Then we can see how valid your statement is that you made.

If this makes me a moron, then I will wear the title with honour.


He thought that he was safe making that statement. Little did he know that this test has been done, very carefully, by a respected manufacturer.

I quoted him the extensive set of tests which proved him wrong without any doubt. Instead of the sample test of one he asked for, I gave him six examples that proved him wrong across calibers from 270 to 458.

His reply?
quote:
I have just skipped your ramblings and twisting of events, as it is just senseless to mull over them.

Roll Eyes
Now he wears the moron title anyway, but without any honour.

PS.
Warrior posted:
quote:
when a water-filled gut is encountered it will rapture
No way that is possible, no matter how much energy or caliber is applied.
 
Posts: 2848 | Registered: 12 August 2002Reply With Quote
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At least we know Warrior will never "rapture."
He be goin' to hell.
 
Posts: 28032 | Location: KY | Registered: 09 December 2001Reply With Quote
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I have tested 7 mm Barnes X-bullets at 25 yds into a wetpack with the follow statistics, and expansion of diameter was exactly the same for all bullet weights, despite an increase in momentum values and SD. The kicker to this was that I stayed within the operating velocity window. I also motioned before that by way of design the drilled hole in the tip was the same for all bullets at which distance the expansion gets arrested regardless of the sectional density

M --------------- V ---------- Mo ------ Mo Index
108 gr --- 2,610 fps --- 40.27 ------- 100
142 gr --- 2,490 fps --- 50.51 ------- 125
175 gr --- 2.390 fps --- 59.75 ------- 148

Here is a top view of the above tested bullets:



Now the loads that you mentioned for the .308 caliber where the velocity is kept the same throughout, but momentum values do go up through bullet weight, follows a very similar pattern looking at the Momentum Index:

M --------------- V ---------- Mo ------ Mo Index
150 gr --- 2,500 fps --- 53.57 ------- 100
180 gr --- 2,500 fps --- 64.29 ------- 120
200 gr --- 2,500 fps --- 71.43 ------- 133

And if we shoot these, the result will be very much the same for a .308 Barnes-X bullet as for the 7 mm bullets that I tested.

Regarding the question that SD drives expansion, I have stated the following before and I quote: .... "I do not say MacPherson is wrong, we need to make sure that we interpret him correctly and not out of context, as you have done before when Alf pointed that out to you. My submission was that bullet construction can limit expansion by design - for example, and I will give a very simple explanation ... If we drill a hole of 2 mm, or 3 mm, or 4 mm, ....... all the way up to 10 mm a Barnes-X bullet , we will have very different expansion, as it rolls up to maximum within its velocity window. If we do not drill a hole in it, it remains a solid and do not mushroom. It is done by the force or momentum behind the tip of the bullet and not because of SD per se - SD is not a force, it is a ratio without motion. Only when velocity is applied will we get momentum and deformation will go up as we apply more velocity that drives momentum values up."

Please note that the above is so, unless expansion is arrested by way of design in the construction of the bullet. The Swift A-Frame bullet also arrests expansion to double diameter and that is why I made the specific statement, as I knew that at that moderate velocity I was within the operating velocity window. Go up in velocity and therefore momentum, and we get a different result .... petals peeling further back (so expansion of XSA becomes smaller, and if we apply more velocity we start to lose all the petals and XSA becomes even smaller.

So what do we learn from this .... we do not work with a stable mathematical relationship ..... so, we have to optimize maximum XSA by staying within the operating velocity window or threshold strength of the bullet. This is the way the light shines for me at this point in time.



Hope this better clarifies my answer.

Warrior
 
Posts: 2273 | Location: South of the Zambezi | Registered: 31 January 2007Reply With Quote
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Doug,

Here is a picture of SD 0.300 North Forks.



9.3 mm through .470 nitro.

I took this picture and it was published in Big Bore Journal and will be soon in African Hunter. (Along w articles to follow).

After shooting about 1,000 rounds of monometals and FMJ's of various makes through the 458, 458 GA, 450 Ackley and 450 Dakota into wood baffle boxes, water tanks, American bison, beef cattle, buffalo and elephant, I have deffinate and well experienced opinion.

The SD 300 is appropriate for monometal solids and probably solid base bonded bullets that are longer than normal FMJ or cup and draw or bonded core soft points.

If you exceed this length (SD) you will have a less well stabilized bullet and or pressure or case capacity issues.

That is why Mike at North Fork very wisely kept to a standard SD of about 300.

He had alot of arm chair experts who wanted it all, a monometal that was heavy for caliber. Cant (or should not be done) in the real world.

There is no mystery here, just common sense.

If you are shooting a FMJ or cup and draw by all means exceed that SD.

I have personally found velocity to be my friend for bonded soft points, and for solids, mass is your friend. (Yes a 500 grain FN will out penetrate a 450 grain FN provided you have enough rotational velocity).

Anyone who does not know this has not gone hunting enough!

Elephant skulls are both hard and wet. The hard part needs mass and the wet part needs a big temporary cavity (velocity).

Best wishes from someone who gets their hands dirty testing bullets, and does not read alot of theory. I look at my emperical data and come up w a theory, while others here start w a theory and stubbornly defend it despite all emperical evidence to the contrary!

Not good scientific method, or predictor of performance on game.

Andy
 
Posts: 1278 | Location: Oregon | Registered: 16 January 2004Reply With Quote
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