[Suhaili]

Hello.
i'm new here, and i want to ask about factors that influenced bullet accuracy. alll the factors except the environmental effect.
and i also want to know is there any equation that i can use to predict bullet velocity at certain range?maybe using its propellant capacity to calculate its velocity at certain range?is it possible?thanks..

[arcticap]

I'm going to try to give you some relatively simple answers.
Some major determining factors affecting accuracy:

a. barrel rifling twist rate - look up the "Greenhill formula".
B. projectile characteristics (length, weight, ballistic characteristics etc...)
c. powder & load characteristics - (velocity, consistency, pressure curve, powder compaction when loaded etc...)
d. barrel integrity characteristics - the quality and length of the barrel and its stock bedding, barrel diameter, cleanliness, temperature etc...

There have been velocity tables published that list the velocities (and sometimes the pressures) of certain projectiles with various BP charges and barrel lengths. Some manufacturers also publish limited velocity and trajectory charts usually derived from actual chronograph testing I believe.
There are also free trajectory programs but they require inputing certain variables.
While calculating anything might be possible, I'm not sure that it would be desirable versus simple chronograph or range testing, or searching out reports of similar bullets and loads that have already been tested by others using chronographs.
And I don't know who if anyone has the actual formulas that would allow for the accurate calculation of the velocity and pressures created by the new proprietory substitute powders, except for maybe their manufacturers.

[Suhaili]

hello arcticap..
thanks for your answer. actuallu, i'm doing about my final year project about replacing the real "accuracy tesy" at bullet manufacturing company at my country using simulation with PRODAS and built an equation using statistical method to determine bullet accuracy without testing them. any idea or information that i could use?
thanks..

[arcticap]

That's very fascinating Suhaili.
It sounds like the PRODAS program would help a company not waste too much time and effort making bullets that are less certain to test well.
I personally don't know of any information or equations that could possibly help you.
Do you have any personal interest in muzzle loaders at all?

Maybe you can find something useful if you search through some links on this Italian website:

http://www.earmi.it/default.htm

Everything below is translated from Italian by http://www.freetranslation.com/

It unloads version for Linux, 220 Kb

WinBallit, ver. 2.0.7-2 - TWO Italian program of ballistics A group of ten or so of years does Johannes Infantryman, in Germany, scrisse a synthetic program in basic to calculate the hunting trajectory of projectiles. I the tradussi in Italian and yourselves inserii routines for the calculation of the ballistics coefficient and to calculate the penetration in material varieties (wood, iron, muscle, bones). Now Stefano Jodice, equipped of the necessary ability of computer program, sacrificed a lot of days of its time free and created a pleasant program of ballistics in Windows that has not nothing to envy the commercial programs.

The data can be introduced in European measures or anglossassoni, also in mixed manner, and with alone two screened calculate all of the data that in the practice can serve to the hunter to the marksman and to the ballistics expert that: - L' kinetic energy - The perforation in the wood, the volume of the cavity in the wood and the loss of speed nell' crossing of a specific thickness of wood. - The iron of slabs of perforation and the remaining speed after the perforation. - The perforation of woven muscular and bony and the speed you limit some skin. - The variations of speed of the
projectile to the to vary some length of the pipe.

The second one screened agrees to calculate with good precision the trajectory of a projectile, with excellent precision until 400 meters and with acceptable precision until one thousand meters. The formulas of the trajectory are not calculated based on the ballistics coefficient, but, more in a modern way, based on the coefficient aereodinamico Cx. The program goes well to calculate every trajectory in which holds not account of a high angle of shot, superior to 5-10 degrees. When they were necessary the data of a generic projectile, of whom it is not known the Cx, does reference to how much written to the page on the factor of shape

All of the programs like this have the natural limit of to be precise alone when the trajectory to calculate is rather short (so talks about hunting trajectory until 300-400 meters) so as to to be able to consider costing the Cx. In very long case of trajectories it would be able to be timely to subdivide it in two or three strokes to calculate separately riducendo the Cx according to the indications ricavabili from the pages indicated and introducing every time the final speed of the previous stroke.

The program is free and can be distributed freely for not commercial usi.

It NOTES: In the previous version with Windows XP is yourselves a mistake of display of the before screened; to use it equally you are thrown the program, then click on Credits and OK; then to click on" CX trajectory" and then to return the before screened (8-X-05).

With the present version the mistake was eliminated.

http://www.earmi.it/download/winballit.htm


Next is about a book:


Exterior Ballistics with Applications
Autore Klimi, Gjergj
Xlibris Corporation
http://www.ibs.it/book/9781436323604/klimi-gjergj/exterior-ballistics-with.html

In the USA just a new outside book of ballistics is gone out written from Gjergj Klimi, at present professor of mathematics to the Peace University of New York. It taught physical and mathematics to the Military Academy of Tirana and that explains its interest for the ballistics. The book itself signal to have united deepened theoretical knowledge, exposed top-level mathematician, to the practice application of the theory, so that ballistics every problem comes illustrated with practical examples of calculation and with edged in Basic for the solution of the problems more communes. It dedicated special caution to the method of the colonel Siacci. one of the ballistics best in absolute. They come treated spaciously the in person fall od objects with parachute and the ballistics of the fragments of projectiles with explosive charge. An absolutely valid work, useful for the students of the Military Schools and for all those who want to confront the problem to create programs of ballistics. The book of 595 pages can be gained to the price of 23.99 dollars + expenditures from Amazon or, in Italy, on the site http://www.ibs.it/book/9781436323604/klimi-gjergj/exterior-ballistics-with.html. I saw with large satisfaction that the author thanks to have used myself the mine "wonderful" pages of ballistics published in this site. It is not yourselves nothing of more satisfying than to discover that I is not alone a sullen jurist!

http://www.earmi.it/varie/klimi.htm


Programs in type and of ballistics
Arms Software
Cart Win - Excellent database for identification of ammunition and boxes; in varied tongues.
Firearms & Supplies Inc. (FSI) - FSI - Ballistics for air compressed JBM Small Arms Ballistics - very spacious Site with ballistics possibility of
calculations in line; is yourselves a bibliography for the outside ballistics and programs to unload
Kostenlos - Situated German for programs, catalogs, free samples Loadammo - Firm produttrice of a good program that unites ballistics functions to data of reloading. Demo in the page Download.
Free - Italian Site for programs, catalogs, free samples Rule - ballistics Program in line - Excellent ballistics progamma in line; asks for an up-to-date browser.
Shareware - Shareware and Gigantic freeware - Shareware and freeware
VOLFTP - Large collection to care of the Telecom-TIN of
programnmi freeware and shareware with description in Italian. Very well-made site and that would deserve to be more known.

http://www.earmi.it/links/default.htm#pro

Theoretical ballistics and practice

Ballistics outside Rudiments of physics

Ballistics in the empty one

Outside ballistics - general Rudiments

I calculate graphic of the trajectory

Ballistics coefficient

The factor of shape the and the ritardazione

To draw a trajectory The ballistics of the diabolo

The ballistics of the caliber 22 l. r.

The stabilization of the projectiles

The vertical shot and the free fall of the projectile - Bombs of airplane

Tables of ritardazione - G1 of Lovry

The shot with large angle of site

I calculate some probability applied to the shot

Mistakes in the shot

The shot in water

Inside ballistics

Inside ballistics

I calculate some resistance of the pipes

The crack pipe-drum

The space of head (Headspace) and the free Route

Terminal ballistics

Terminal ballistics

The thin perforation of slabs

The power of stopping

Hunting ballistics

I calculate some hunting trajectory

The shot to long distance

The rebound of the projectiles

The strangling

Slug - Ballistics of the balls slug and shot to the pigskin

The shot to the roebuck and the arms

Ballistics of the balls and of the spherical projectiles

Ballistics of the balls - The rosy one

Ballistics of the ball of steel

I calculate some speed of an arrow

The caliber

The I recoil

You deduce varied and historians

Acoustics of the I fire The caliber of the ancient artilleries

Well-known cannons - The Large pile Driver and the Cannon of Paris

Effectiveness and precision of the ancient arms

The ballistics gelatine

The Ballistics Pendulum

Introduction to the muzzle-loading

Air compressed - to measure the Joules

Bibliography of the arms and of the ballistics

Explosives

In these pages we want to we supply the some ballistics of notion readers in very practical manner and without the superior use of mathematics, doing instead run back to formulas approached and to graphic methods. Not always it is had available a program of ballistics and do not always it agrees to obtain all the information wanted. Programs of ballistics I am rinvenibili to the page Download.

http://www.earmi.it/balistica/default.htm



Lastly, there's some naval formulas on this page along with references to other formulas to search for that may be relevant:

The Le Due formulas of course are subject to revision as more exact8 methods of determination of velocities and pressures are introduced. They have, however, given good results. For example, in the case of the 16-inch 45-caliber gun, the powder charge and the maximum pressure, determined before the gun was built, were on actual firing found to be very nearly exact.

DERIVATION OF LE DUC FORMULAS
(See Table I for explanation of symbols)

http://www.eugeneleeslover.com/USNAVY/CHAPTER-III-PAGE-1.html

http://www.eugeneleeslover.com/USNAVY/CHAPTER-III-TABLE-I.jpg

http://www.eugeneleeslover.com/USNAVY/CHAPTER-III-TABLE-III.jpg

[scrat]

problems with this.


One of the problems we have found is this. A manufacture can claim there bullet will travel at a certain speed to achieve a given result. From full ammo cased (brass with powder, primer bullet) to bullet manufactures ( bullet only sold as projectile). The problem with this is they use Test guns and test barrels to gather this information. These test wil be different from us using them. Unless you have the same gun, barrel and in the same condition. So it maybe possible to make a program to (estimate) the performance of a bullet. However the actual test is when its fired through a real gun. Then this may change from gun to gun.

In the handloading section. Alot of us try to duplicate loads from published books. Books where in print a manufacture may have results from using a specific load. So we try to use the same load. When chronigraphed though the results vary. Thus we have to adjust the load to get the same desired effects.

[Jim Watson]

Well, MY objective is to shoot the gun. I will use computer simulations for rough work like getting on target (see below) but will dismiss most others as advertising claims not substantiated on the range.

Exterior ballistics does not boil down to simple equations; manual calculations are extensive as shown in Hatcher's Notebook.

Given the measured muzzle velocity (consumer chronographs are not expensive) and the bullet's ballistic coefficient (available from manufacturers of jacketed bullets and computed or determined empirically by trials using two chronographs at different ranges for cast) you can use readily available computer programs to estimate bullet velocity and trajectory for different ranges. That is good enough to get you "on paper" at a known distance, but an actual zero and accuracy determination require shooting the gun.

[scrat]

Jim i agree 100%. thats why the computer will never replace the gun. Kinda reminds me of a bore sighter. People think when they use one the gun will be dialed in with the scope. However in reality the boresighter just gets you on paper. you still have to go to the range and shoot the gun at different yardages and fine tune it in.

[Suhaili]

hello arcticap,jim and scrat..
thanks for a lot of advise and information from all of you..now i want to explain a little bit of my project to all of you..actually, what i am doing is just for the test barrel at the manufacturing site..my project didn't involve the real gun shooting yet..from my research, there are no paperwork or study to do such a thing like my project yet..maybe after my project is successful, some further research can be done to determine bullet's accuracy at the real gun shooting process..my factors that i take for determine bullet's accuracy for my accuracy estimation are just the projectile's (bullet's) weight and the propellant..because at the manufacturing site, the test is conducted at the indoor shooting range..from the shooting range supervisor, he said that all the environmental factors that influence bullet's accuracy, can be assume, eliminated..my final year project adviser, ask me to add another factor, that is the bullet velocity at certain target..that is why i need an equation to determine bullet's velocity at certain target..do any of you have some information on bullet's velocity at certain target?ammunition that i used is 9mm Ball Parabellum..maybe its velocity at 100m and 200m?i have search at the internet and in the book, but i couldn't get this information..do any of you familiar with Mean Radius or Figure of Merit?the term used to describe bullet accuracy..

[Suhaili]

hello arcticap,jim and scrat..
thanks for a lot of advise and information from all of you..now i want to explain a little bit of my project to all of you..actually, what i am doing is just for the test barrel at the manufacturing site..my project didn't involve the real gun shooting yet..from my research, there are no paperwork or study to do such a thing like my project yet..maybe after my project is successful, some further research can be done to determine bullet's accuracy at the real gun shooting process..my factors that i take for determine bullet's accuracy for my accuracy estimation are just the projectile's (bullet's) weight and the propellant..because at the manufacturing site, the test is conducted at the indoor shooting range..from the shooting range supervisor, he said that all the environmental factors that influence bullet's accuracy, can be assume, eliminated..my final year project adviser, ask me to add another factor, that is the bullet velocity at certain target..that is why i need an equation to determine bullet's velocity at certain target..do any of you have some information on bullet's velocity at certain target?ammunition that i used is 9mm Ball Parabellum..maybe its velocity at 100m and 200m?i have search at the internet and in the book, but i couldn't get this information..do any of you familiar with Mean Radius or Figure of Merit?the term used to describe bullet accuracy..

[higene]

Deleted

[Jim Watson]

9mm Para in the blackpowder section?
Oh, well.

I take it that this is for an academic research project.
If so, please post our grade here when done.

Please ask your English professor for remedial education on capitalization, punctuation, sentences, and paragraphs. Your posts are very hard to read and comprehend.

I belive that down range velocity is part of the results from the trajectory program at:
http://www.eskimo.com/~jbm/calculations/traj/traj.html
The terms are explained so you can enter appropriate data.
You will need the ballistic coefficient of the bullet. Many are given at:
http://www.shootforum.com/forum/bulletdb.html
If the exact bullet you use is not listed, the best approach would be to take an average of the various bullets of the same type. 9mm Ball projectiles are similar enough to give a reasonable approximation.
I know of no simple equation that will do the job, it is an involved calculation made to seem simple by computer power. Study the JBM material and have at it.

Mean radius and figure of merit are discussed at:
http://www.frfrogspad.com/miscellh.htm#mean

(Do you have Google? This was very easy to locate by a search.)

"Q. What does the target measurement "mean radius" mean?

A. The "mean radius" is simply the average distance of all shots from the center of the group. To compute the mean radius draw a horizontal line just below the group and the measure the height of each hole above that line and the average those measurements. Using a vertical line do the same thing and average the distances. These two measurements will locate the center of the group. Then measure the distance from the group's center to each hole and average those measurements. The result is the "mean radius."

Another similar measurement (though not often heard of) is called the "figure of merit." To find it, draw a line through the center of the lowest shot in the group and then measure the vertical distance to the center of the highest shot in the group. Do the same with the shot farthest to the left and measure to the farthest right shot. Average these two measurements.

Both of these measurement are seldom used outside of the military but are much better indicators of ammunition consistency than group size."

[Suhaili]

hello higene and jim..
thanks for the information, higene but i do not use the energy calculation in my research..for jim, thanks for all the information that you gave me..when i'm done with my research i'll make it up to all of you that have help me..
thanks..

[modwerdna]

I really think this is not the correct location to post this q&a.

This is about black powder shooting, where we try to coax the best out of antique styled guns burning a mixture of charcoal, sulfur, and potassium nitrate.

Ignited by a rock and a piece of steel hurling a round ball swaddled in a piece of my old favorite jeans lubed with spit, or animal fat. Hardly a science of what pc program big companies should use to choose bullet shapes for tack driving target rifles.

Sounds like your topic requires a white lab coat, cup of coffee and a pocket protector. Ours requires a deerskin jacket ,some comfy moccasins , a coon skin cap, a tin of some good old shine.

All I know is, I set my sight's on ole 6 point with my short gun 50 at 70 yards, and tickled the trigger and 40 grains of ffg sent a 490 ball through his heart and after the smoke cleared, I was a fixing some tenderloins for supper!

Now that's black powder!

[Suhaili]

can anyone give me the vector pistols (9mm Ball Parabellum) dimension?the most important part is the barrel length and diameter?where can i get it?

[Jim Watson]

See descriptions of the Vector pistols at

http://digitalsushi.com/midashi/website.mirrors/guns/world.guns.ru/handguns/hg54-e.htm

http://digitalsushi.com/midashi/website.mirrors/guns/world.guns.ru/handguns/hg30-e.htm

Barrel lengths are given, barrel diameters, - I presume you want internal diameter for ballistics calculations - will be a problem to determine. A reasonable standard would be a bore diameter of .348" (8.84mm) and a groove diameter of .355" (9.02mm). The guns are stated to have "polygon" barrels which do have some effect on ballistics but not much.

[Suhaili]

thanks jim..
i do have another favor to ask..where can i get schematic diagram or detail drawing of vector SP1 & SP2..i have to draw the vector pistol to make analysis in PRODAS..in PRODAS, they didnt have the drawing for vector pistols..