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duke76
06-05-2007, 07:00 PM
This may have been asked before and I know the answers are probably going to vary quite a bit but I am looking for a general rule of thumb on velocity for:
1. Air cooled WW with gas check and 50-50 lube or LLA
2. Water queched WW with gas check 50-50 lube or LLA
3. Air cooled WW without gas check 50-50 lube or LLA
4. Water quenched WW without gas check with 50-50 lube or LLA
5. Pure lead with a little tin with 50-50 or LLA

All of these should be considered out of a average barrel.

Bass Ackward
06-05-2007, 07:16 PM
Ain't the velocity. It's the pressure.


This is the formula for making the Calculations: ALLOY: BHN X Tensile Strength (480) = Factor, Factor X 3 = Minimum Chamber Pressure (psi), 4 X Factor = Maximum Chamber Pressure (psi)



Examples for common mixtures:


PURE
LEAD 5: 5 X 480 =2400, 2400 X 3 = 7,200 psi, 2400 X 4= 9,600 psi




1-20 LEAD / TIN 8: 8 X 480 = 3840, 3840 x 3 = 11,520 psi, 3840 X 4 = 15,360 psi




WHEEL
WEIGHTS 12: 12 X 480 = 5760, 5760 X 3 = 17,280 psi, 5760 X 4 = 22,040 psi




LYMAN
#2 15: 15 X 480 = 7200, 7200 X 3 = 21,600 psi, 7200 X 4 = 28,800 psi




LINOTYPE 22: 22 X 480 = 10560, 10560 X 3 = 31,680 psi, 10560 X 4 = 42,240 psi




HEAT TREATED
WHEEL WEIGHT 30: 30 X 480 = 14400, 14400 X 3 = 43,200 psi, 14400 X 4 = 57,600 psi

duke76
06-05-2007, 10:52 PM
OK I can agree with that, now how much does it change with a gas check, because you obviously cannot drive a pure lead boolit as fast as you can just because it has a gas check.

454PB
06-06-2007, 10:48 PM
I've been using WW metal and gas checked boolits in many handgun loads up to 1600 fps, and the same ammo in rifles up to 1900 fps.

As an example, my maximum effort .454 Casull loads are theoretically (using industry figures, I don't have a strain gauge) around 50K psi pressure.

Bass Ackward
06-07-2007, 05:50 AM
OK I can agree with that, now how much does it change with a gas check, because you obviously cannot drive a pure lead boolit as fast as you can just because it has a gas check.


Duke,

Since it depends on pressure, case capacity is a big factor. So is barrel length. The general consensus for PB seems to be 1600 fps. Using a 26" 22-250, I can tell you lead starts to leave vapor trails at 3200 fps and won't reach 100 yards at 3500 fps. In my 06, 14 BHN just beyond 2600 fps. In my 458X2, 2100 fps is the top accurately.

See a trend?

Lloyd Smale
06-07-2007, 06:52 AM
as bass has stated theres alot more to it then just leading. It doesnt do you a bit of good to push a cast bullet to 1600 fps out of a handgun if it isnt shooting accurately at those speeds. I cant get as technical as bass about why but ive yet to see cast out of any sixgun accurate at 1600 fps out of any alloy. Now before theres shooting matches about this understand that my idea of accurate may be differnt then yours. I bench my guns and expect at least 2 inch groups at 25 and a realated level of accuracy out to a 100 yards. My idea of accurate isnt being ablet to hit a beer can at 50 yards 5 out of 6 times. Also one thing i am as experienced about as any on hear is cast bullet penetration and pushing that bullet to 1600 fps out of any alloy is a waste of time. Ill gurantee that it will do a better job at 1200 fps. Now if your looking for a bullet to shatter or expand you can no doubt do it better at 1600 fps But to me that isnt what cast bullets in a handgun are all about. The abiltiy to break bone penetrate straight at any angle into the vitals is what they do best.

joeb33050
06-07-2007, 07:27 AM
Ain't the velocity. It's the pressure.
This is the formula for making the Calculations: ALLOY: BHN X Tensile Strength (480) = Factor, Factor X 3 = Minimum Chamber Pressure (psi), 4 X Factor = Maximum Chamber Pressure (psi)
Examples for common mixtures:
PURE
LEAD 5: 5 X 480 =2400, 2400 X 3 = 7,200 psi, 2400 X 4= 9,600 psi
1-20 LEAD / TIN 8: 8 X 480 = 3840, 3840 x 3 = 11,520 psi, 3840 X 4 = 15,360 psi
WHEEL
WEIGHTS 12: 12 X 480 = 5760, 5760 X 3 = 17,280 psi, 5760 X 4 = 22,040 psi
LYMAN
#2 15: 15 X 480 = 7200, 7200 X 3 = 21,600 psi, 7200 X 4 = 28,800 psi
LINOTYPE 22: 22 X 480 = 10560, 10560 X 3 = 31,680 psi, 10560 X 4 = 42,240 psi
HEAT TREATED
WHEEL WEIGHT 30: 30 X 480 = 14400, 14400 X 3 = 43,200 psi, 14400 X 4 = 57,600 psi

When we got to this topic while writing the book I was very interested and hoping that this pressure hardness relationship was one of the rules to live by for accurate CB shooting.
At the end of ~ 3 months of pretty intense study and work, I and others concluded that this-above-and the other similar notions are without foundation and are just not true.
If this or some other of the formulae were true, it is somewhere between difficult and impossible to reliably measure BHN or chamber pressure outside of a laboratory setting, so using the formula would be impossible for the common man. Or woman.
For more on this, including a list of articles from which this business is derived, see the book at http://sports.groups.yahoo.com/group/CB-BOOK/, look in FILES, then 3.3 "CAST BULLET HARDNESS REQUIREMENTS".
This tells the story as well as we were able to put it together.
I find it annoying that legends or urban myths such as this have a life of their own, that they will go on and on. The characteristics of a myth like this seem to be precisely defined coefficients, mentions of such engineering or scientific terms as "ultimate compressive strength" (look it up, it's got nothing to do with lead), frequent mention of words such as, my favorite, "obturation", and a precise description of just exactly what goes on in the chamber of the gun when the fire is lit.
I read about this on the LASC page and frequently see mention of one of this family of pressure/BHN/accuracy myths; generally quoted by someone who is honestly believing the tale.
We wrote the story in the book, I don't expect to make this legend go away, but every now and then I feel impelled to write something like this.
joe brennan

felix
06-07-2007, 08:05 AM
Joe, I do not know of the legend you are speaking about. Please be extremely specific in reply. ... felix

Bass Ackward
06-07-2007, 08:20 AM
Joe,

Oh I agree hole heartedly. Under good conditions it can be beat all to hell.

As an example, is this a handgun chart or a rifle chart? Handguns have shorter barrels and must have pressure applied at a faster and higher rate than a long barreled rifle. We all understand inertia.

What this chart does do though, is to acquaint the new booliteer to pressure / velocity relationships. People always think it's the velocity. Even experienced guys fall into the trap.

This allows the inexperienced guy to use about any lube or store bought bullets and have success in almost any bore condition in any temperature range until they gain the confidence to try and beat it. It merely prevents leading from extremes one way or the other.

In other words, it's VERY conservative, but an EXCELLENT trainer.

pdawg_shooter
06-07-2007, 08:29 AM
Two wraps of 16lb paper changes everything. 200 gr. WW cast bullet, sized .301 and patched up, 2926 fps from a 300 RUM gave 1.5" at 100 yards. Pressure? My old Powley says around 58000 if it was jacketed, Lot less pressure with paper.

joeb33050
06-08-2007, 09:53 AM
Joe, I do not know of the legend you are speaking about. Please be extremely specific in reply. ... felix
Felix;
the legend is that there is a precise relationship between maximum chamber pressure, accuracy and bullet BHN.
For more, and to understand what all the contenders wrote, see the chapter in the book.
joe brennan

felix
06-08-2007, 10:30 AM
Actually, there is a precise relationship involving (not exclusively) pressure, accuracy, and projectile hardness. Fact is, nobody has related all the variables to make up the precise relationship. ... felix

drinks
06-08-2007, 11:00 AM
I can get good results at 2500fps + with a/c wws, gas check and the slowest powder that will deliver the velocity while using LBT soft blue or Lar's high speed red in .243, .308 and 35 Whelen.

leftiye
06-08-2007, 05:56 PM
Joe, So you're saying there is no relationship between boolit hardness and the boolit's ability to resist deformation from pressure? Or just that you couldn't figure it out (precisely)?

If there is no relationship at all, we're all then operating under some waaay misguided ideas.

Doesn't EVERY metal resist deformation more or less as it is hardened or softened (metals that can be hardened or annealed that is)? Aren't there limits of elasticity (plastic limits) for tensile strength, compressive strength, and yeild strenght (bending) well established for all of the metals and layed out in the metals handbooks? Doesn't it accomplish more if we try to figure things out rather than continually expanding the "Unknowable Territories?"

waksupi
06-09-2007, 03:18 AM
For those who don't recognise the factor between chamber pressure, and projectile deformation, I once again, throw the BS flag.
I don't have time to go into it tonight. Any blacksmith can most likely jump in with some good comments, though.

joeb33050
06-09-2007, 06:30 AM
Actually, there is a precise relationship involving (not exclusively) pressure, accuracy, and projectile hardness. Fact is, nobody has related all the variables to make up the precise relationship. ... felix

I think that this says that there IS a precise relationship between the three. My question is, "How do you know that?" I'm very willing to learn.
joe brennan

joeb33050
06-09-2007, 06:50 AM
Joe, So you're saying there is no relationship between boolit hardness and the boolit's ability to resist deformation from pressure? Or just that you couldn't figure it out (precisely)?

Why is it that people who write "so you're saying...." piss me off so.
I didn't say that and don't mean that. On another forum I wrote:

The beginner wants to know what alloy to use. Me too.

WW or WW and a little tin, although I never saw the need for the tin for many years, is the easiest alloy to find.

Some SS shooters believe that "pure" lead tin alloys are needed-their velocities go up to 1500 fps. Other SS shooters use WW/WW+ALT

WW/WW+ALT in plain based bullets work fine up to 1500 fps.

WW/WW+ALT in GC bullets works fine up to 1800 fps.

Linotype is pretty easy to find.

Linotype and GC bullets work fine up to 2200 fps

Any accuracy work above 1800 fps and any work above 2200 fps requires advanced knowledge and techniques.

Now this was written to prompt response and arguments to the contrary, but the only response was agreement. And I recognize that there is overlap and that bore condition and powder choice and bullet fit contribute.


If there is no relationship at all, we're all then operating under some waaay misguided ideas.

Never said that, never meant that. Suu just above.

Doesn't EVERY metal resist deformation more or less as it is hardened or softened (metals that can be hardened or annealed that is)?

That's a definition.

Aren't there limits of elasticity (plastic limits) for tensile strength, compressive strength, and yeild strenght (bending) well established for all of the metals and layed out in the metals handbooks?

Not a lot of data on lead alloys, I have what little I and others could find. It took me a long time to figure out about tensile strength, compressive strength and yield strength; and lead alloys.

Doesn't it accomplish more if we try to figure things out rather than continually expanding the "Unknowable Territories?"

I'm intensely interested in figuring things out about cast bullets; that's why I did and am doing the work. I was very interested in the pressure/accuracy/BHN relationship, worked long and hard with others to understand and document this relationship; and was very disappointed to find the contention absolutely unsupported. This isn't an "Unknowable Territory" at all, we have thousands of examples of accuracy/BHN/pressure combinations available to us. I couldn't find any relationship, maybe you can do better.
Read the chapter and prove me/us wrong; that's what I want. Because I'm intensely interested in figuring thing out about cast bullets.
joe brennan

joeb33050
06-09-2007, 06:55 AM
For those who don't recognise the factor between chamber pressure, and projectile deformation, I once again, throw the BS flag.
I don't have time to go into it tonight. Any blacksmith can most likely jump in with some good comments, though.

Certainly with BP the bullet will expand to fit the grooves.
Probably with smokeless in some circumstances the bullet will expand.
In the smokeless case we were unable to find the connection between pressure, BHN and accuracy.
Maybe I just don't understand the "Factor".
I'm ready to learn.
joe brennan

Bass Ackward
06-09-2007, 07:46 AM
I think that this says that there IS a precise relationship between the three. My question is, "How do you know that?" I'm very willing to learn.
joe brennan


Accuracy is not a .... factor, but the end result. You can't understand it in those terms unless you broaden away from those to include every thing else that pertains or contributes. That includes harmonics, bore condition, temperature, twist rate, yada, yada, yada.

A bullet can make or break accuracy for sure. But bullet fit affects how much pressure a certain hardness can take. Same with design. If that peak, where ever level it is, doesn't occur on a harmonic node, then it ain't going to be worth much. And if you have a better bore condition, you don't need as much hardness either. Where are the harmonic nodes? Well that depends on bedding and barrel length and a bazillion things here too doesn't it? Right down to the stress in the steel.

And pressure alone isn't a factor since it's really the rate the pressure is applied that over comes inertia. While a bullet might fail at 25,000 psi from Red Dot, it may handle 35,000 from 4831. And inertia changes by bullet weight and by bore diameter.

So trying to find a "relationship" has to imply consistency. Consistency with cast occurs at 1300 to 1800 fps. Many people that don't understand this subject, believe that best accuracy occurs in this area. That's crap. Easiest accuracy occurs there. Above that area, you are in a whole new world. Variables are magnified and amplified. Especially bore condition and harmonics. What may be smooth enough or dimensionally correct at 1300 to 1800 just won't cut the mustard on up. And you have to learn how these things interact to be able to work around, correct, change or advance. Lube will change friction. Change friction, you change vibration. Change vibration, you change harmonic patterns. Change harmonics, and you change sweet spots or nodes. And thus the hardness you need to get there.

If you don't shoot high velocity cast in rifles, this lesson may never be understood. If it isn't, then true understanding is virtually impossible. If it isn't understood, then you believe that the best cast accuracy occurs at low velocity and that long range performance is really about bullet design. High velocity which results from higher pressure cast is an open class taught by Professor Gun and his assistant Mr. Target. They encourage your participation.

joeb33050
06-09-2007, 08:21 AM
Accuracy is not a .... factor, but the end result. You can't understand it in those terms unless you broaden away from those to include every thing else that pertains or contributes. That includes harmonics, bore condition, temperature, twist rate, yada, yada, yada.

A bullet can make or break accuracy for sure. But bullet fit affects how much pressure a certain hardness can take. Same with design. If that peak, where ever level it is, doesn't occur on a harmonic node, then it ain't going to be worth much. And if you have a better bore condition, you don't need as much hardness either. Where are the harmonic nodes? Well that depends on bedding and barrel length and a bazillion things here too doesn't it? Right down to the stress in the steel.

And pressure alone isn't a factor since it's really the rate the pressure is applied that over comes inertia. While a bullet might fail at 25,000 psi from Red Dot, it may handle 35,000 from 4831. And inertia changes by bullet weight and by bore diameter.

So trying to find a "relationship" has to imply consistency. Consistency with cast occurs at 1300 to 1800 fps. Many people that don't understand this subject, believe that best accuracy occurs in this area. That's crap. Easiest accuracy occurs there. Above that area, you are in a whole new world. Variables are magnified and amplified. Especially bore condition and harmonics. What may be smooth enough or dimensionally correct at 1300 to 1800 just won't cut the mustard on up. And you have to learn how these things interact to be able to work around, correct, change or advance. Lube will change friction. Change friction, you change vibration. Change vibration, you change harmonic patterns. Change harmonics, and you change sweet spots or nodes. And thus the hardness you need to get there.

If you don't shoot high velocity cast in rifles, this lesson may never be understood. If it isn't, then true understanding is virtually impossible. If it isn't understood, then you believe that the best cast accuracy occurs at low velocity and that long range performance is really about bullet design. High velocity which results from higher pressure cast is an open class taught by Professor Gun and his assistant Mr. Target. They encourage your participation.

You've got a lot of highfalutin words here, ya got harmonics and sweet spots and nodes and mustard; but my rule is that if I read it 4 times and still don't understand, it may not be me. What's the point? You introduced the BHN/pressure/accuracy myth to the discussion, do you believe that it is true?

I shoot low velocity cast loads, seldom above ~1600 fps, and I do so for a set of reasons.
I have never found better accuracy at higher velocities.
LV means the barrel lasts for a long time, maybe my lifetime. HV will reduce the accuracy of a rifle with CBs fairly quickly. I know, I've done it.
LV allows WW or similar soft less expensive alloys.
LV means reduced recoil, I like low recoil.
LV allows no gas checks, money and time.
LV means accuracy fully equal to HV, see the PBB SS rifle results. HV ain't beating them.
Now, if you like HV, or want to hunt and think you need HV, or want to shoot long range or gas guns or ??? and think you need HV, then God bless you-go right ahead.
I've read and tried HV loads from Rifleman articles in the 50s. I can shoot 170 grain HARD GC bullets at ~2700 fps with slow powders in 30/06, but not with accuracy.
Accuracy is what I want, and you're right, accuracy is fairly easy to find below 1800 fps. But, if you think that HV yields better accuracy, you are dead wrong, and the match results prove it.
No "harmonic node" business takes the place of the target.
joe brennan

felix
06-09-2007, 09:50 AM
Joe, what John said is correct. Please try and think through it mo'betta'.

The acceleration of the bullet/boolit is what determines harmonics. The projectile must accelerate the very same each time. In reality, we cannot make this happen. But what we can do is alter the powder giving the best accuracy in steps around the point giving the best accuracy. While doing so, the increment before and aft of the set point must be large enough to represent the ability of the powder measure to maintain forever in terms of powder energy volume (not weight). Each round should each be about perfect for the situation: the gun system plus ambient. If not, then another powder should be used, or another primer. (John, the spot where we want the projectile to leave the barrel is exactly half way between two nodes, because that is where the rate of change of the vibe would be zero). ... felix

drinks
06-09-2007, 11:14 AM
Joe and others, try, the-long-family.com on search, you will come up with several hits that go into a very detailed discussion of interior ballistics.
Ultimate Barrel Timing is a very good one and there is quite a bit of discussion on it.
A friend , who is a research scientist and dedicated shooter and reloader, is trying out the theory and math and having VERY good results.

leftiye
06-09-2007, 11:45 PM
When we got to this topic while writing the book I was very interested and hoping that this pressure hardness relationship was one of the rules to live by for accurate CB shooting.
At the end of ~ 3 months of pretty intense study and work, I and others concluded that this-above-and the other similar notions are without foundation and are just not true.
If this or some other of the formulae were true, it is somewhere between difficult and impossible to reliably measure BHN or chamber pressure outside of a laboratory setting, so using the formula would be impossible for the common man. Or woman.
For more on this, including a list of articles from which this business is derived, see the book at http://sports.groups.yahoo.com/group/CB-BOOK/, look in FILES, then 3.3 "CAST BULLET HARDNESS REQUIREMENTS".
This tells the story as well as we were able to put it together.
I find it annoying that legends or urban myths such as this have a life of their own, that they will go on and on. The characteristics of a myth like this seem to be precisely defined coefficients, mentions of such engineering or scientific terms as "ultimate compressive strength" (look it up, it's got nothing to do with lead), frequent mention of words such as, my favorite, "obturation", and a precise description of just exactly what goes on in the chamber of the gun when the fire is lit.
I read about this on the LASC page and frequently see mention of one of this family of pressure/BHN/accuracy myths; generally quoted by someone who is honestly believing the tale.
We wrote the story in the book, I don't expect to make this legend go away, but every now and then I feel impelled to write something like this.
joe brennan


So what exactly did I miss? You listed B.A.s outline, and proceeded to say that it and outlines like it were "without foundation" and "just not true" (see above). Then measuring BHN became "impossible" outside of a lab, and the guidelines are therefore useless anyway (NOT). Talk about what Pi$$es people off, it may be some people's use of terms like "myths", "Legends" etc.. You forgot "old wives tales", another of MY favorites! Thank the force I've not become perfect yet.

joeb33050
06-10-2007, 07:14 AM
So what exactly did I miss? You listed B.A.s outline, and proceeded to say that it and outlines like it were "without foundation" and "just not true" (see above). Then measuring BHN became "impossible" outside of a lab, and the guidelines are therefore useless anyway (NOT). Talk about what Pi$$es people off, it may be some people's use of terms like "myths", "Legends" etc.. You forgot "old wives tales", another of MY favorites! Thank the force I've not become perfect yet.

Lefty;
Did you read the cite? If you did and you find errors, I'd like to know. If you didn't, why are you talking about it? I/we did the work, we dug out the articles and did the testing. I said above, "it is somewhere between difficult and impossible to reliably measure BHN or chamber pressure outside of a laboratory setting"; you misquoted. Read the article and then criticize, otherwise you're being foolish.
joe brennan

joeb33050
06-10-2007, 07:44 AM
Joe and others, try, the-long-family.com on search, you will come up with several hits that go into a very detailed discussion of interior ballistics.
Ultimate Barrel Timing is a very good one and there is quite a bit of discussion on it.
A friend , who is a research scientist and dedicated shooter and reloader, is trying out the theory and math and having VERY good results.
Drinks;
Thanks for the info; I just printed the 17 page Ultimate Barrel Timing article; it will take a while to get this into my head.
joe brennan

Bass Ackward
06-10-2007, 07:51 AM
You've got a lot of highfalutin words here, ya got harmonics and sweet spots and nodes and mustard; but my rule is that if I read it 4 times and still don't understand, it may not be me. What's the point? You introduced the BHN/pressure/accuracy myth to the discussion, do you believe that it is true? joe brennan


Joe,

Sorry Joe. I expected that you wouldn't understand something since you haven't been successful doing it. Not much I can do to help you with your outlook. But harmonics? Come on. Everybody that has ever thrown a powder charge and increased / decreased it and saw accuracy change at least knows what harmonics does.

When I was able to get accuracy just as good at 2600 fps as you could get from the Marshall load outta my rifle, I had to spend some time digesting it. Once you see and do that, you are forced to try and repeat it. I have repeated it in every rifle, every caliber, I own so far.

If you have good bore condition, you can at least match your best low velocity accuracy efforts. What you have to do is much more spcefic and limiting. You can do it with Red Dot anymore. But if you break a .... rule once, it is no longer fact.

That means that: "best accuracy comes at 1600 - 1800 fps in a 30 caliber" goes on the list of "old wives tales" for me. (leftiye just loves that line :grin:) I just keep my mouth shut when someone says that because for him, with his knowledge base or data, .... it's true.

Most limits to cast bullets are self imposed and therefore old wives tales.

When satisfaction is achieved, all experimentation and learning stops.

sundog
06-10-2007, 08:08 AM
Joe, I was going to read your stuff, but I choose not to join the group, which is apparently needed in order to read the files. If this is so important to you, then put the material where it is a little more readily accessable.

leftiye
06-10-2007, 04:35 PM
Sundog, Second that. Joe, I don't understand how you can put up a post, mention your book, and expect us to read it before we get to comment. We're dealing with comments made here and references are fine only so long as they're accessible and reasonable to expect someone to spend the time to read. I reacted to what you DID say, and your dismissal as a misquote is really stretching it. You did use the term impossible, and to add add difficult to that doesn't change much. So you can avoid the issues and argue about details if you want, and you'll succeed because I'll stop wasting my time, but you'll still be wrong, and you'll still not be answering the issues.

buck1
06-10-2007, 07:22 PM
A long pressure curve has been the biggest factor in better group size at higher speeds that I have found.
I never felt speed in itself hurt my bbl so much as the prolonged exposure to the large doses of hot burning gas/ powder. (catch 22) But I could be wrong. I havent known everything since I was 16 years old......Buck

joeb33050
06-11-2007, 05:59 AM
Joe, I was going to read your stuff, but I choose not to join the group, which is apparently needed in order to read the files. If this is so important to you, then put the material where it is a little more readily accessable.

The book is up on the Yahoo forum cited. It is free to all, and most folks find it easy to access. The forum isn't about talking back and forth, messages are few and mostly about book construction. Anyone can join the forum and set preferences to keep from ever getting any messages.
Or, send me your e mail address and I'll send you the chapter.
(We'll soon have CDs in 3 formats available)
joe brennan

joeb33050
06-11-2007, 06:09 AM
Sundog, Second that. Joe, I don't understand how you can put up a post, mention your book, and expect us to read it before we get to comment. We're dealing with comments made here and references are fine only so long as they're accessible and reasonable to expect someone to spend the time to read. I reacted to what you DID say, and your dismissal as a misquote is really stretching it. You did use the term impossible, and to add add difficult to that doesn't change much. So you can avoid the issues and argue about details if you want, and you'll succeed because I'll stop wasting my time, but you'll still be wrong, and you'll still not be answering the issues.

This thread was originally about hardness and velocity, with accuracy understood.
I wrote that we had spent a lot of time, did a lot of work and some experiments, and concluded that the "3 X 480"/"1422" family of stories were without merit-weren't true.
If you can't get to the book to read the chapter, send me your address and I'll e mail it to you. See above.
But, if you or anyone else won't take the time to read cites, then what can I say? Some of the cast bullet business is difficult to understand, it's hard and takes some work.
We're dealing with a complex topic here, and to get a grip on it, one must be willing to do the reading.
If anyone wants to voice an opinion without the reading, go ahead-but that opinion will be suspect.
Is that fair?
joe brennan

Bass Ackward
06-11-2007, 07:39 AM
We're dealing with a complex topic here, and to get a grip on it, one must be willing to do the reading.
If anyone wants to voice an opinion without the reading, go ahead-but that opinion will be suspect.
Is that fair?
joe brennan


Joe,

A complex topic? Heck yes it's complex. In order to lay out everything though, we need to define what makes an accurate barrel. Then we can reproduce it. When all barrels are made .... just as accurate .... then we can look for .... rules or facts or definitions. But without making a reproducible barrel, we are simply spinning our wheels looking for research into sub-related areas.

I have been on record as saying this was not correct. But do we really need to do work today to prove it? All one has to do to blow that chart out of the water is to go back about 70 years to the Keith load for his bullet in 44. He stated this was tested at HP White Labs at 34,000 psi. That's a 10 BHN bullet.

Find one flaw in research and it is no longer fact. That chart is a guideline to show a relationship between hardness and pressure. That's all it is. It warns a guy not to use store bought rocks for a 38 special without understanding bullet fit. It tells him not to use pure lead PB for full power 454 Casull. When one guideline, like 1300-1800 fps is broken, should it be dismissed?

Generalities. And one generality is just as valid as another because there is no rule for how many times it has to be correct and no way to record how many times it is violated. If research leads to false understanding that then is presented to be fact, that's where I have problems with it.

This board is full of examples of guys finding accuracy with different calibers in the 2500 to 3000 fps range. Hell they are doing it with levers in the 2000-2500 fps range! Is this new to us? Have we broken new ground? I have an old Lyman manual from 1958 (I think) that guys talk of 2700 fps with certain designs back then. Who knows how far back it goes? So this ain't Star Trek here. We are just reinventing the wheel.

leftiye
06-11-2007, 04:09 PM
Actually generalities seem more functional in this medium. There are ( as has been said) very few "RULES" (and there aren't any rules at all if one or a few exception invalidates them) that are absolute. However, if one can get a feel for "generalities" that are relable, maybe with a little COMMON SENSE he can get predictable and good results.

Nitpicking $*k$. Joe, this thread didn't ever become about your reference to your book. If the reference is vital to your comment, maybe you should type a little bit more.

454PB
06-12-2007, 12:30 AM
BA makes the point I was trying to show. Theoretically, my .454 Casull loads should not work as well as they do using WW alloy.......they exceed the accepted pressure limits by a wide margin.

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