Rifle Accuracy Facts

Take the following Book, Rifle Accuracy Facts Written by Harold R. Vaughn . If you would like to improve your shooting, I strongly strongly advise to buy, read, understand Vaughn's Book, then act accordingly.

Rifle Accuracy Facts Written by Harold R. Vaughn This book makes the definitive study, made over a number of years, by a leading research scientist, on the subject of why some rifles shoot very well… some shoot fairly well… and others shoot poorly. C1278 (Wt. 2 lbs.)..$29.95
http://www.creedmoorsports.com/C1278.html

Book Review

by Duncan MacPherson

Rifle Accuracy Facts
Vaughn, Harold R.
Precision Shooting, Inc.
222 McKee St., Manchester, CT  06040 soft cover $34.95, hard cover, $39.95 +$3.50 S&H 290 pages, many photos, figures, and graphs

            A book review in V3#3 of the Wound Ballistics Review and a comment on this review in V3#4 brought up the issue of a good book describing exterior ballistics for the general reader.  I said I didn’t know of one then, and Rifle Accuracy Facts is not devoted to this subject, but will fill this purpose for many readers.  With this as an introduction, we will go back to a standard review format.

            Harold R. Vaughn is an engineer whose distinguished technical career was spent at Sandia National Laboratories in flight dynamics and aerodynamics.  He retired in 1986, and devoted his considerable technical skills to an orderly analysis and test program to understand and demonstrate what factors contribute to making rifles shoot more accurately.  I called Mr. Vaughn to discuss some technical details not relevant here, and we had an interesting discussion about small arms and technology.  We both deplore the fact that modern engineering capabilities and techniques are so little used by those interested in small arms.  There is little hope that this situation will be rectified anytime soon by the firearms and ammunition manufacturers, who are forced to be very bottom line oriented in this very competitive market.  The amount of money required to run a laboratory that could revolutionize understanding of a variety of small arms features is relatively modest, but there is little hope for anything like this anytime soon.  The few government facilities that might fund this work do not have staff with the required technical skills, and there is no obvious other source for the money.  As a result, the primary source of advances in understanding is talented individuals who are willing to devote their own resources and efforts to this end for the satisfaction of accomplishment.  That is what Mr. Vaughn has done in the area of rifle accuracy, and fortunately, he has not only done this well, but has written it up well in Rifle Accuracy Facts.

            Readers should be under no illusions; Rifle Accuracy Facts is not light reading, and not for anyone who thinks Guns and Ammo is a technical publication.  Rifle Accuracy Facts is a superb book; most attentive readers will understand all or almost all the material in the main text.  On the other hand, almost all readers will find that they have little or no interest in most of the appendix material (about 20% of the total) even though this will be invaluable to readers who wish to do sophisticated experimentation on their own or who are interested in detailed equations.  The bulk of Rifle Accuracy Facts is a detailed description of Mr. Vaughn’s experimentation in making rifles shoot more accurately.  This work is a true technical advance in understanding this issue, and the description of this work is interesting in its own right.  Anyone seriously interested in rifle accuracy should own this book.

            Anyone who wants a solid understanding of either interior or exterior ballistics should get this book even if they are not interested in rifle accuracy.  The descriptions of interior and exterior ballistics (one chapter each) are both precise and understandable without forcing the reader to follow the details in a lot of equations.  The important equations are there for readers who want them, but can be skipped without losing comprehension for readers not technically oriented.  Each of these chapters could be “puffed up” to longer length and some readers might prefer this, but the information is efficiently imparted in the chapters as written and I personally prefer this approach.

            Perhaps the best summary of the contents of Rifle Accuracy Facts is the chapter description given on the contents page of the book:

1. Introduction:  Contains data on the accuracy to be expected from different types of rifles and background information on why and how this work was done.
    

2. Internal Ballistics:  Methods of measuring chamber pressure are discussed and the complete internal ballistics of a representative cartridge (.270 Winchester) are measured experimentally for use in later chapters.  Such things as bullet engraving force, different powders, and cartridge case failure are discussed.
    

3. Chamber and Throat Design:  Methods of machining chambers and throats and their effects on accuracy are discussed.  Various types of rifling and barrel problems are analyzed.
    

4. Barrel Vibration:  Detailed measurements and theoretical calculations of barrel vibration are presented along with methods of reducing barrel vibration.  The effect of barrel vibration is measured on sporters, bench rest, and rail guns.
    

5. Scope Sight Problems:  Scope sight and scope mount problems are investigated and some solutions to these problems are found.
    

6. Barrel-Receiver Threaded Joint Motion:  It was experimentally determined that the barrel-receiver threaded joint moves as a result of the shock from firing.  A simple solution to the problem is described.
    

7. Muzzle blast:  The effect of bullet in-bore cant and muzzle blast on dispersion were determined experimentally and theoretically.  Methods of reducing dispersion from this source are presented.
    

8. Bullet Core Problems:  Bullet core slippage due to the spin up torque is measured and found to be a problem.  Other bullet problems are analyzed.
    

9. Bullet Imbalance:  The static and dynamic imbalance of bullets is measured and the effect of imbalance on dispersion is evaluated theoretically and experimentally.  The causes of bullet imbalance are discussed.
    

10. External Ballistics:  The detailed motion of the bullet after leaving the muzzle is shown and the effect of this motion for a given initial disturbance is evaluated.  The effect of wind, gyroscopic stability factor, and ballistic coefficient on the bullet’s trajectory are shown in detail.  Chronograph development and use are discussed.  Wind gauges and their use is covered.
     

11. Other Problems:  Miscellaneous Problems, such as bore cleaning, bullet coating, drift free bullet design, case neck tension, and shooting techniques are discussed.

Appendices: Accelerometer design, barrel vibration computer equations, bullet balance device design, six degree of freedom computer equations, tunnel range construction, rail guns, shadowgraph testing.

As the chapter descriptions indicate, most of the material in Rifle Accuracy Facts is related to rifles, not handguns.  However, those interested in handgun interior and exterior ballistics should not despair.  The material in chapters 2 and 10 uses rifle bullets as examples, but the principles also apply to handgun bullets.

            Reviews are supposed to describe the book’s shortcomings, but I found only two small faults, neither important to most readers for different reasons.  There is a typographical error in the equations for F1 and F2 on page 187 (exponent ½ on wrong bracket), but this will be recognized by most people attempting to use this equation and is of no importance to anyone else.  The second topic is in the Chapter 11 discussion of “moly coated” bullets (the relatively recent technique of coating bullets with molybdenum disulfide and carnauba wax).  Vaughn has done testing of some claims relative to the effects of moly coating bullets and has very interesting comments on several issues, but is essentially neutral on the effects of extended barrel life because he hasn’t proved this.  This is a good example of how careful Vaughn is in making claims, a stance that many others in ballistics would do well to emulate.  The careful distinction Vaughn makes throughout the book between what he has demonstrated and his speculations is laudable and very evident here.  However, in this instance the advantages of properly moly coated bullets in extending barrel life have been established beyond reasonable dispute by many others, and Vaughn’s “could be true” is unnecessarily weak even though he hasn’t personally verified this.  Again, readers who care will know this, and it doesn’t matter for the others.

            Rifle Accuracy Facts is going to be recognized as a classic in years to come, you will be glad you got it.

Duncan Mc Pherson

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From: "Sam Nichols" <snichols@lcc.net> To: <fullbore@hawk.winshop.com.au> Sent: Sunday, January 20, 2002 5:22 PM Subject: Re: [Fullbore] Bullet imbalance


Lutz and Larry, Have either of you or any listers used the Vern Juenke's International Concentricity Comparator (I. C. C.) According to the evaluation, that is quite capable of detecting bullet imbalance in bullets making trying to compensate for the imbalance unnecessary. I have never seen or used this device but you can see the evaluation in it's entirety at: http://www.shootingsoftware.com/reloading.htm Below is a copy of the text the evaluation of this device by the people at: Recreational Software (http://www.shootingsoftware.com/index.htm) A very interesting site with evaluation of reloading equipment and techniques and design of better devices for reloading.

It doesn't actually x-ray your bullets but Vern Juenke's Internal Concentricity Comparator (I. C. C.) seems to. This device uses sonic pulses to look "inside" bullets for concentricity problems caused by voids and jacket irregularities. One past International Heavy Rifle Champion says, it is the secret to shoot 6 inch groups at 1000 yards. If you do everything else correctly, and still get an occasional flyer, it may be your bullets. Weighing bullets can not tell you if an entire box was made from jackets with walls that are thin on one side. But, if the lead core is not centered they can fly as bad as the worst out-of-round projectile. Top competitors with one of Vern's machine often use only 40% of the best hand swaged bullets for serious work. You may find only 10% of the less expensive or production bullets you have been using measure to "Golden BeeBee" standards, with as many as ¼ or more actually measuring as "junk".

Sam

That's a Reason, why turned Bullets shine: See LM-105

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