In Harold Vaughn's Rifle Accuracy Facts , Chapter 6, "Barrel-Receiver Threaded Joint Motion", he develops the theory that the barrel-receiver joint is a major source of inaccuracy in rifles.

Vaughn's test vehicle is a Remington 721. Based on his theory, Vaughn is able to predict group flyers immediately before the flyer is shot from a machine rest in a shooting tunnel.

On page 120, Vaughn's cure for these flyers looks a lot like a Savage barrel nut added to the Remington 721.

Any thoughts ?

Hammer

It is next to impossible to make a threaded joint that has zero “play†between the parts...especially when you add expansion/contraction due to heat and sudden extreme pressure, vibration, etc, like you have in a firearm.

What you might want to consider though is that in BR matches (for those using non custom receivers) Remington’s will outnumber Savage’s by about 10 to 1.

Vaughn does a lot of good work in his book but he is a little quick to jump to conclusions, IMHO. His barrel attachment solution is quite a bit more complicated than the Savage barrel nut.

If movement at the barrel/receiver joint is a huge problem, then how is it that some custom switch-barrel bolt guns, the kind with the barrel screwed on hand tight, seem to shoot OK at least by hunting standards?

Then there are the Ruger 10/22's with the non-threaded barrel sloppily attached to the flexible aluminum receiver with a single bolt. In theory, this is a terrible thing, and some people have gone to the trouble to attach the barrel with threads or else attach the scope to the barrel with a cantilevered mount. Yet most any aftermarket barrel with a match chamber will turn the 10/22 into an MOA or better tackdriver, sloppy barrel attachment notwithstanding.

If barrel attachment is a significant problem, as Vaughn suggests, then it could be solved by a cantilever scope mount -- then if the barrel moves relative to the receiver, the scope would move along with it. The barrel could also be pre-loaded either with pressure bedding or with a 10/22 type attachment bolt. Then if the barrel did wobble relative to the receiver, the pre-loading would tend to return the barrel to an equilibrium position.

Vaughn's book is worth reading just because it makes you think about some things that you haven't thought about before, but some of his stuff his questionable. He seems to seek out the most complicated way to do things. That seems to be a characteristic of engineers who work in the defense industry courtesy of our tax dollars.

quote:

Originally posted by popenmann:

.... If movement at the barrel/receiver joint is a huge problem, then how is it that some custom switch-barrel bolt guns, the kind with the barrel screwed on hand tight, seem to shoot OK at least by hunting standards?

.... He seens to seek out the most complicated way to do things. That seems to be a characteristic of engineers who work in the defense industry courtesy of our tax dollars.

If memory serves me right, lots of benchrest rifle barrels are screwed on hand-tight.

At least in the '70s, Fred Sinclair built at least one on a Remington 700 that way.

Hammer

I’ve read the book and while it offers some useful (though extremely techinical) info the author seems obsessed with things so tiny that it all practical matters they are irrelevant in the real world.

The only way to have no movement at all at the barrel receiver junction is to do away with it completely by machining the reciever and barrel as a one piece unit...which ain’t very practical.

It is also relevant to note that the difference between a record group today (with all our modern technology) and a record group 70 years ago is pretty damned small and is probably less than the size of a dime or maybe a nickel.

I've seen a fair bit of commentary about Vaughn's work in that book but saw little reason to question much of what he said. He stated up front that he was dealing with a sample of one for most of the work, and most of it was making points of illustration I think, rather than recommending everybody go out and adopt what he found. I don't recall much of the detail on the barrel nut discussion, but do recall some part of his comments regarding the Spira-lock threads for enhancing the receiver/barrel union. Some have used this approach, but I have no idea if a hunting rifle can show any measurable improvement over conventional thread unions.

quote:

Originally posted by Rick 0311:
the author seems obsessed with things so tiny that it all practical matters they are irrelevant in the real world.

.

this is called PII
pursuit of irrelevant increments/improvements

jeffe

quote:

Originally posted by jeffeosso:

quote:

Originally posted by Rick 0311:
the author seems obsessed with things so tiny that it all practical matters they are irrelevant in the real world.

.

this is called PII
pursuit of irrelevant increments/improvements

jeffe

jeffe,

I like that...and I must confess to having been guilty of it myself on more than a few occasions!

Perhaps, but Vaughn was smitten by two flaws. His life was moulded by the minutae of aeroballistics, and his interest in BR shooting. As far as usefulness goes, I'd never heard of bullet cores slipping inside the jackets prior to his writing the book, and wonder how often the resulting inaccuracy is attributed to other factors. I think he illustrated the fact of the occurrance amply with his .270.

quote:

Originally posted by Hammer:
In Harold Vaughn's Rifle Accuracy Facts , Chapter 6, "Barrel-Receiver Threaded Joint Motion", he develops the theory that the barrel-receiver joint is a major source of inaccuracy in rifles.

Vaughn's test vehicle is a Remington 721. Based on his theory, Vaughn is able to predict group flyers immediately before the flyer is shot from a machine rest in a shooting tunnel.

On page 120, Vaughn's cure for these flyers looks a lot like a Savage barrel nut added to the Remington 721.

Any thoughts ?

Hammer

I think Vaughn was right. The solution I like is to use Spiral-Lock thread tooling. The only 'smith I knows who does so is Greg Tannel [www.gtrtooling.com]. The spiral-lock tooling is expensive and proprietary but it substantially improves the strength of the thread joint.

Jordan

If movement in the threaded joint is really a problem all you need is a tapered locating area. Maybe even a parallel one, maybe about 1/8" long. Prairie Gun Works in Winnipeg Canada used to do this on thier Ti-15 model. This was long before Remington marketed the 700 TI. PGW's locating fit was at 45 degrees. Not hard to incorporate. Parallel locating fits with no more than .0002" to .0003" clearance at both ends of the thread would work well also. A lot of the down-hole drilling equipment we build at our shop is threaded together this way. Not rocket science.

Does bedding the barrel instead of free-floating it have anything to do with this issue ?

Hammer

I enjoy Vaughn's book, and think people who critisize it should write there own book with all the backup info to dis-prove his work.

With that said, I have always wondered why he chose a 270 as a sample gun/caliber. This is in no way an accurate cartridge, by BR standards, and there are no BR quality bullets available in that size. Bullet quality has been one of the biggest contributing factors in the way current BR guns perform today.

In my opinion Vaughn's book is the best "gun book"
I ahve ever read. Those taking shots at it have either never read it, or can,t understand it.
How can you put someone down for being intellegent, and detail oriented. People who drive
auto's, fly in planes, and use computers love to tell how stupid engineers are, go figure.
Good luck!

quote:

Originally posted by hawkins:
How can you put someone down for being intellegent, and detail oriented. People who drive
auto's, fly in planes, and use computers love to tell how stupid engineers are

I'm an engineer and I have serious issues with much of Vaughn's work. As I said before, he is quick to jump to conclusions. His experiments are too complicated and introduce new variables instead of isolating variables. He omits most of his raw data and calculations -- we are supposed to trust him because he is a genius and we are mere idiots.

For example, if I were going to test the hypothesis that the barrel is wobbling on the receiver, I'd try comparing accuracy with a cantilevered scope mount attached to the barrel vs. the normal receiver mounted scope. That would be a simple apples-to-apples test of the same barrel. Instead, Vaughn tries different barrels with different means of attachment. Since different barrels are used, you don't know if accuracy differences are due to the different barrel or due to the different means of attachment.

His experiment that allegedly proves that lead cores slip or shear inside the jacket is laughable. At one point he assures us that the lead core actually melts -- not true as cast bullet shooters prove all the time. At another point he claims to prove with calculations that the lead shears -- also not true as proven by cast bullet shooters. At no point does he test his theory by shooting a single cast bullet. Instead, he devises a ridiculously complicated experiment that introduces new variables and new sources of measurement error. Typical Vaughn.

As I said before, it's a good read because it makes you think -- just don't be naive enough to believe everything he says. Don't assume that he knows what he is talking about just because he is an engineer -- Uncle Sam's DOD/DOE is chock full of incompetent engineers who wouldn't be able to make the grade in the private sector, where you have to produce tangible results on time and on budget. Don't assume that his experiments are full of meaning because many of his experiments are actually poorly designed -- a good experiment is simple, easy to measure, and isolates variables, but Vaughn's experiments tend to be just the opposite. I give Vaughn an A+ for effort, and an A+ for original thinking, but a C- for effectiveness.

quote:

Originally posted by rembo:
If movement in the threaded joint is really a problem all you need is a tapered locating area. Maybe even a parallel one, maybe about 1/8" long. Prairie Gun Works in Winnipeg Canada used to do this on thier Ti-15 model. This was long before Remington marketed the 700 TI. PGW's locating fit was at 45 degrees. Not hard to incorporate. Parallel locating fits with no more than .0002" to .0003" clearance at both ends of the thread would work well also. A lot of the down-hole drilling equipment we build at our shop is threaded together this way. Not rocket science.

Rick,
The tapered seat is indeed a good system to increase rigidity of the joint. We used this "fix" on some hydraulic dump cylinder rods which were having a problem breaking off at the the joint between the rod and piston. By the way, these were a 5" diametr rod and the tenon onto which the piston (8 inch dia) was threaded was 3 1/2 " in diameter. The incorporation of a 45 degree seat at thew shoulder of the rod ended the problem.
I had spoken to Ross Spagrud about the use of a tapered seat and barrel shoulder on an action many years ago. He may well have already been doing it though. I seldom have an original idea!
The use of the Spiralock threads is a means of making a loose thread fit tight. The system depends upon the deformation of either barrel or receiver threads to achieve a tight fit. It was originally intended as a self locking mechanism for nuts and bolts.
As many have mentioned many times, the use of conventional threads and barrel fitting techniques have resulted in accuracy so good that it is difficult to mount a reasonable argument condemning these practices. Regards, Bill.

Just looked at Greg Tannel's site, gtrtooling.com, as suggested by Jordan. Very interesting stuff.

quote:

Originally posted by hawkins:
How can you put someone down for being intellegent, and detail oriented. People who drive
auto's, fly in planes, and use computers love to tell how stupid engineers are, go figure.
Good luck!

If I remember correctly it was an aeronautical engineer that said bubble-bees couldn’t fly!

I'm an engineer and I have serious issues with much of Vaughn's work. As I said before, he is quick to jump to conclusions. His experiments are too complicated and introduce new variables instead of isolating variables. He omits most of his raw data and calculations -- we are supposed to trust him because he is a genius and we are mere idiots.

For example, if I were going to test the hypothesis that the barrel is wobbling on the receiver, I'd try comparing accuracy with a cantilevered scope mount attached to the barrel vs. the normal receiver mounted scope. That would be a simple apples-to-apples test of the same barrel. Instead, Vaughn tries different barrels with different means of attachment. Since different barrels are used, you don't know if accuracy differences are due to the different barrel or due to the different means of attachment.

His experiment that allegedly proves that lead cores slip or shear inside the jacket is laughable. At one point he assures us that the lead core actually melts -- not true as cast bullet shooters prove all the time. At another point he claims to prove with calculations that the lead shears -- also not true as proven by cast bullet shooters. At no point does he test his theory by shooting a single cast bullet. Instead, he devises a ridiculously complicated experiment that introduces new variables and new sources of measurement error. Typical Vaughn.

As I said before, it's a good read because it makes you think -- just don't be naive enough to believe everything he says. Don't assume that he knows what he is talking about just because he is an engineer -- Uncle Sam's DOD/DOE is chock full of incompetent engineers who wouldn't be able to make the grade in the private sector, where you have to produce tangible results on time and on budget. Don't assume that his experiments are full of meaning because many of his experiments are actually poorly designed -- a good experiment is simple, easy to measure, and isolates variables, but Vaughn's experiments tend to be just the opposite. I give Vaughn an A+ for effort, and an A+ for original thinking, but a C- for effectiveness.[/QUOTE]

A couple of points:
Firing cast bullets at velocities and pressures of jacketed bullets might shed some insight onto your theories as well. Give it a try sometime.
Cast bullets are not necessiarily the same alloy as used in jacketed bullets either. The rifling engraves the cast bullet where its not the case with a jacketed bullet.

A scope on the end of the barrel will tell you static misalignment but not dynamic inconsistancy. Vaugn was looking for dynamic variation from the time the primer ignited to the time the bullet left the muzzle. And had the barrel instrumented as such. Its interesting to note that there are some 1,000 - 1,200 yd folks that have an optical sight on the muzzle but its mainly for accounting for barrel deformation due to a long shot string.

Jim Borden P.E. a engineer as well will tell you Harold Vaughn is right on the money.

I'll agree with you on the assessment of government employees in general not just engineers. If You were a minority, female, disabled war vetran you would have the job regardless of competance.

Know lets see from what I'm told an M1 Abrams or some artillery guns accuracy in terms of MOA will make a Benchrest Shooter hang his head in shame. So someone must know what they are doing at Aberdeen or wait isn't that where Harold Vaughn worked.
Now lets see M1 Abrams, smooth bore, solid, fin stabilized projectile, muzzle instrumentation, how about the breech threads probabably buttress, acme or square? I wonder if Vaughn was looking over someones shoulder with all those ideas?

I know a couple of people that have published works, mostly research/reference guides.

It seems that the publishers don't seem to want much more than the "thought starters" as far as technical detail...and after reading their original work, and what ends up getting published are so far out of line its unbelievable. They don't want the math or machining detail or explanations on complex measuring or comparison/statistics - they're worried that when average Joe picks up the book he's going to see formulas/machines/processes etc., that he's not familiar with and set it back down.

Granted these kind of books are written for a limited audience...but somebody is publishing it trying to make money.

I ordered this book the first time it showed up in the pages of Precision Shooting - spent a week reading and re-reading the things I didn't grasp, then researching things I didn't think the author covered to the extent I needed for my understanding.

After handing it off to a friend(one of those who has been published), his initial reaction was that it had been edited my the same person that edited his book....and chopped it to hell.

After thinking about it, I have to agree. There are certain things that go into detail to the nth degree, and others that are seemingly more important to the topic that are absolutely skimmed over.

If I had to guess, I think the publisher/editor worked the original book over something fierce.

quote:

Originally posted by rws:
With that said, I have always wondered why he chose a 270 as a sample gun/caliber. This is in no way an accurate cartridge, by BR standards, and there are no BR quality bullets available in that size. Bullet quality has been one of the biggest contributing factors in the way current BR guns perform today.

I think that Vaughn chose the 721/.270 because it would be more likely to show improved groups than an extremely accurate BR cartridge/barrel. It was in the beginning of his book or was mentioned on one of the boards by someone that was friends with him.

quote:

Originally posted by DemoSam:
Firing cast bullets at velocities and pressures of jacketed bullets might shed some insight onto your theories as well. Give it a try sometime.

Do it all the time. No evidence of the bullet stripping the rifling on recovered bullets. The American Rifleman published articles on fine accuracy with paper-patched lead bullets at 3000 fps. There are many other problems with lead bullets -- slumping, canting, fouling, imbalance, and gas cutting -- but rarely failure due to spin shear, unless something is terribly wrong.

The G forces caused by the forward acceleration of the bullet are an order of magnitude greater than the G forces caused by spin, so while there are accuracy issues associated with spin, especially after the bullet leaves the barrel, while the bullet is in the barrel it's much more likely to suffer from the effects of forward acceleration.

quote:

A scope on the end of the barrel will tell you static misalignment but not dynamic inconsistancy.

Regarding dynamic vs. static, Vaughn's claim was that the barrel moved relative to the receiver-mounted scope from one shot to the next due to flex at the barrel threads. He claims he proved this by mounting a scope on a mandrel that he slid into the muzzle in between shots. His mandrel-mounted scope would shift from shot-to-shot compared to the the receiver mounted scope -- or so he said, though I have a hard time believing that a slip-fit mandrel could be accurate enough to prove anything. Let's say that Vaughn is right and the barrel really is wobbling around on the receiver from one shot to the next. If that's true, then the problem could easily be solved just by mounting the scope on the barrel, either with a scout scope type arrangement or else with a cantilevered mount like the Volquartson mount for the Ruger 10/22. No fancy threads or fancy experiments required.

If you follow Vaughn's theory, TC contenders and other break open single shots should be inherently more accurate than bolt guns, since the SS's aren't plagued with wobbly barrel threads. Every serious benchrest shooter should immediately trade in his bolt action for an H&R Handi-Rifle.

Even though I pick nits with Vaughn, I do admire him very much for attempting a logical and scientific approach to our hobby. I wish more shooters would do the same, only with a little more care and a little less arrogance.

I have not read any of this Vaughn characters work, but I do have one simple question? If anyone cares to answer! If you do not fully tighten the wheel nuts on your car the rim works loose and in time the tire falls off. If there was any play between a barrel and action why does the barrel not work loose? If there was any movement ........... Even microscopic movement between the barrel and receiver would cause it to loosen up. Unless I’ve misunderstood the whole thing it has a ring of witch craft to it. Its only common mathematics and physics. Any thoughts? Rod Henrickson

Vaughn measured the barrel movement and found it to be consistant with the shift in the point of impact. He then changed the threading, based upon stress analysis not conjecture, and cured the problem. That may have beeen only one sample but it was convincing.
I spoke with him a while before he died. My call was to congratulate him on the first logical explaination of why the wind drift of a bullet is a function of the velocity loss.
Before the "experts" belittle his work they should read it.
There is as much BS written about guns as there is about politics, every man is born an expert.
Good luck!

The question of flex at the barrel threads is an intelligent question and I give Vaughn credit for asking the question and making me think about it. Yet, at the same time I poke fun at Vaughn's work because of his sloppy engineering and sloppy documentation. Was his mandrell-mounted scope accurate enough to measure barrel movement? Vaughn claims the mandrell error was +/- 0.3 MOA, but he doesn't back up that claim with measurements or tests. The reader is expected to take his word for it. The reader is expected to take Vaughn's word for almost every claim in the book, and that's the problem.

As a freshman engineering student, I didn't receive full credit for my work unless I clearly stated my assumptions and my hypothesis and showed all calculations. In freshman labs, I was required to estimate the error of my measurments. I was required to take enough measurements to be statistically meaningful, and I was required to do statistical analysis on the final results. And last but not least, all of this work had to be carefully documented. This method of doing things is drilled into every engineer, or at least it was when I went to school. If you want to be taken seriously in the scientific community, that's how you do things. Vaughn should have known that. Maybe Vaughn's data and calculations were deleted by the editor, but my take is that Vaughn had such a high opinion of himself that he felt he was above scrutiny.

Getting back to the original question, I don't claim to know the answer to the barrel thread issue, except to observe that most of us expect a custom bolt gun with standard barrel threads to shoot better than we can hold, and that bolt guns in general seem to be as accurate as other actions that don't have barrel threads, and that any possible accuracy problems caused by thread flex could easily be solved by attaching the scope to the barrel instead of the receiver.

quote:

Originally posted by speerchucker30x378:
I have not read any of this Vaughn characters work, but I do have one simple question? If anyone cares to answer! If you do not fully tighten the wheel nuts on your car the rim works loose and in time the tire falls off. If there was any play between a barrel and action why does the barrel not work loose? If there was any movement ........... Even microscopic movement between the barrel and receiver would cause it to loosen up. Unless I’ve misunderstood the whole thing it has a ring of witch craft to it. Its only common mathematics and physics. Any thoughts? Rod Henrickson

Rod,

Living where you do, do you know anyone who puts a squirt of oil or a dab of grease on their lugs nuts before they screw them on for protection against rusting? If you do, where does the lubricant go if there is no gap at all between the male and female threads????? You ever use pipe tape for plumbing... Where does it go???

There is no such thing, that I am aware of, as a complete 100% fit between any male and female thread.

If it were possible (which I don’t believe that it is) to cut the male and female threads perfectly, 100% indentical, in size that fit would be destroyed the first time they were screwed together...assuming that one had the physical strength to do that!

Gunsmithing and reloading and actually much of the firearms industry and language has a lot of mental masturbation involved.

It's fun to think about but gets you absolutely no where.

If it was the case that it (in some manner) actually improved accuracy it would have been discovered years ago. It may indeed contribute in a minute manner but so little as to evade detection.

If I was a benchrest shooter I might be more interested but there seems little applicable to hunting accuracy here.

A wise man once told me that if something doesn’t make a difference...then there is no difference.

I have tried and tried to find accurate directions to the “theoretical world†and the “perfect world“ over the years and just can’t ever seem to find them. Oh, well, I guess I’m just stuck here in the “real worldâ€...for the time being anyway.

quote:

... I have tried and tried to find accurate directions to the “theoretical world†and the “perfect world“ over the years and just can’t ever seem to find them. Oh, well, I guess I’m just stuck here in the “real worldâ€...for the time being anyway.

On a clear day you can go up to Cumberland Gap National Park just outside of Middlesboro, Kentucky and see Virginia, Kentucky, and Tennessee. You can get a glimpse of the theoretical world just at sunset some times.

On the night of a full moon you can go up to Cumberland Falls State Park near Corbin, Kentucky and see the perfect world if it is the second full moon within one calender month provided the humidity ain't too bad.

Babamkulu
Philosopher

quote:

Originally posted by hawkins:
My call was to congratulate him on the first logical explaination of why the wind drift of a bullet is a function of the velocity loss.
Before the "experts" belittle his work they should read it.
Good luck!

hawkins,

I have his book, and I enjoyed reading it just as I enjoy reading any book on firearms because you can always learn something.

He makes some very valid points, but he also puts forth an awful lot of information, that while great for mind teasing conversation, has absolutely no bearing on 99.9999% of human activity with firearms.

It’s sort of like discussing and debating how bullets fly when fired in a vacuum. Who the hell cares????

Do it all the time. No evidence of the bullet stripping the rifling on recovered bullets. The American Rifleman published articles on fine accuracy with paper-patched lead bullets at 3000 fps. There are many other problems with lead bullets -- slumping, canting, fouling, imbalance, and gas cutting -- but rarely failure due to spin shear, unless something is terribly wrong.

The G forces caused by the forward acceleration of the bullet are an order of magnitude greater than the G forces caused by spin, so while there are accuracy issues associated with spin, especially after the bullet leaves the barrel, while the bullet is in the barrel it's much more likely to suffer from the effects of forward acceleration.

If you follow Vaughn's theory, TC contenders and other break open single shots should be inherently more accurate than bolt guns, since the SS's aren't plagued with wobbly barrel threads. Every serious benchrest shooter should immediately trade in his bolt action for an H&R Handi-Rifle.

Even though I pick nits with Vaughn, I do admire him very much for attempting a logical and scientific approach to our hobby. I wish more shooters would do the same, only with a little more care and a little less arrogance.[/QUOTE]


Why did they need to paper patch the bullets and what causes fouling? I would expect heat and friction.

When you talk of spin shear you are not taking into consideration the rifling is engraving the lead more in your example than it would if it was surrounded by a copper jacket nor are you considering the fit of the core relative to the jacket.

You shoot 99+% lead cast bullets at 55,000+ psi over 3,000 fps. With no lube or paper all the time. I don't believe it.
So why aren't the BR guys using cast bullets, by your logic?

Accuracy bullet makers go to extensive lengths in their process to prevent core jacket slip or have a gap between the core and jacket. The problem Vaughn measured does exist in production bullets today albiet less today than years past.

Now since you are an engineer. Would you design a 1" diameter pressure vessel with a stub shank, v-threads and a square shoulder cut into its diameter which needs to be axially concentric to its mating component while being exposed to impulse pressures in excess of 65,000 psi repeatedly?
I know its used but is it the best way?

BR smiths go to great lengths to fit the threads between the barrel and receiver and there can be problems with that type of interface. I don't know of any smith that will guarantee .1 or .2 MOA from a rifle. Why because they can't produce a system delivering that accuracy consistantly. The Houston Warehouse had alot of BR smiths and shooters scratching their heads wondering what was wrong when they couldn't blame the shooter or conditions.

Interpreting Vaughns logic as TC and Handi rifles as being superior is quite a stretch for even an engineer. It's been awhile since I read my copy and its on loan but I thought there was a followup article published by him that explained a system with tension bolts and a press fit reciever barrel junction. Since you mentioned handi rifles David White's results may surprise you, I believe he has a web page.

If I remember correctly the muzzle was instrumented with an accelerometer. But as far as a scope mount for the muzzle why you have to be able to measure relative to the reciever at the same time? What he did was accurate enough to find the problem he was looking for based on shot dispersion and would have used something more accurate if he needed to.

The only problem with Vaughns work was not many are intellegent enough to understand it and he left alot of other experiments he did out.

Rick next time you install a barrel try leaving a shoulder on the barrel that will impact against the shoulder on the action and this may take the slop out of the threads when you tighten up the barrel. I have a feeling that the oil that you put on the threads may just flow to areas where the threads do not meet perfectly. Some one once told me that it is impossible to cut male and female threads that meet perfectly. But what do I know. Rod Henrickson

rod,

Read your own post and pretend it was written by someone else...or maybe you don’t have to pretend!

Am I reading it wrong or do you not state that if there was even a “microscopic†amount of play in the threads that the barrel and receiver joint would work loose?

Originally posted by speerchucker30x378:
I have not read any of this Vaughn characters work, but I do have one simple question? If anyone cares to answer! If you do not fully tighten the wheel nuts on your car the rim works loose and in time the tire falls off. If there was any play between a barrel and action why does the barrel not work loose? If there was any movement ........... Even microscopic movement between the barrel and receiver would cause it to loosen up. Unless I’ve misunderstood the whole thing it has a ring of witch craft to it. Its only common mathematics and physics. Any thoughts? Rod Henrickson

Well Rick things don’t seem to compress very much. All things being equal. I know that you can crush the hardest steel with the power of oil. Sooooo ...... if you have a layer of oil between 2 layers of steel there should be no movement! After all the oil is solid. It only acts as a liquid! Rod Henrickson

Hey, man...whatever you say is fine with me.

I think Mr. Vaughns book was very interesting but above some heads[mine included] in some cases. I did an experiment for a customer/friend with his "Spirolock Threading" and the shooter couldnt seem to find much difference, if any, between it and the standard V threading. BTW- He was a benchrest type shooter and pretty well known too. I do remember it was a somewhat costly deal as the Spiro-lock was a patented or copywrited thing and he had to get the tooling at a high price. It is probably still sitting in a corner someplace. The reading was tedious for me in places as my math [algebra] skills are lacking so my beloved wife had to translate for me. He did put a VAST amount of time etc into the tests and book though. Maybe I`ll re-read it this winter.

Aloha, Mark

When I question Vaughn's theories I am playing the devil's advocate and pointing out some gaps that need to be filled. That doesn't mean that I disagree with Vaughn -- I am simply undecided due to insufficient information. I suspect some of Vaughn's theories will eventually prove out while others may not.

Vaughn made himself an easy target by being so pompous and by omitting so many details. For that he has no one but himself to blame.

Contrast Vaughn's writing style to Mann's or Hatcher's or Ackley's.

Dr. Mann comes across as very modest and unassuming, even though he was a medical doctor and an inventor who made a fortune at an early age with his inventions. Mann's book is mostly page after page of meticulously gathered and meticulously documented experimental data. Mann shows his calculations, too. He repeats some experiments over and over again in different barrels and different calibers to prove that the results were not a fluke. It makes for dry reading, but most of his theories have stood the test of time because of all that data.

Hatcher is not as technical as Mann, but neither is he as pompous as Vaughn. Hatcher tells you what he knows and doesn't stretch it beyond that.

Ackley is a little closer to Vaughn's style -- lots of fantastic claims but he doesn't go into detail on how he measured velocities and pressures. Today, most of us take Ackley's load data with a grain of salt. Ackley does do some very worthwhile blow-up experiments and that's about the only thing from his book that still seems worth reading.

I'm going to give Vaughn's book a second read. Even though I've poked fun at Vaughn, I do recommend the book because it makes you think.

athat's odd, when I read vaughn's book I didn't find him pompus. He took pride in his work, as he should have. There is much in the book to think about. For example barrel whip is due to asymmetry of the receiver, not the barrel. As I mentioned earlier he explained wind drift for the first time that I had read it anywhere. I don't know of another book that has actual information of this type, Ackley assumed a lot that was not really so.
Good luck!

quote:

Originally posted by hawkins:
athat's odd, when I read vaughn's book I didn't find him pompus. He took pride in his work, as he should have. There is much in the book to think about. For example barrel whip is due to asymmetry of the receiver, not the barrel. As I mentioned earlier he explained wind drift for the first time that I had read it anywhere. I don't know of another book that has actual information of this type, Ackley assumed a lot that was not really so.
Good luck!

hawkins,

Not in any way to diminish his work, but what is so special, or ground breaking, about his explanation of the effect of wind on a projectile in flight.

Also, in ballistics, “deflection“ is actually the proper term for side movement caused by wind...â€drift†is caused by spin and gyroscopic precession and is independent of the effects of wind on the bullet, even though the two can act together in moving the bullet sideways, and even slightly up or down, during its flight.

That’s the reason that the old 1903 Springfield rear sights were called a “drift slide.†As the slide was raised for longer ranges it moved to the side slightly to compensate for the “drift†of the bullet caused by the spin imparted by the rifling.

Have you ever asked why wind drift of a bullet
is a function of the velocity lost, and not the time of flight?. Even Jack OConner spoke of the wind pushing on the tail of "long" bullets.
The wind does not "push" on the side of the bullet at all. The bullet turns into the wind so that the angle of attact is zero. Now the drag has a downwind component that causes drift.
If you have read that information anywhere else
please let me know. There is so much BS out there Vaughn helped us a lot.
Good luck!