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[ i -- Exterior Ballistics -- QBALL ]
=====================
D E D I C A T I O N
---------------------
QBALL was inspired by the many computer programs
published in The American Rifleman, and is
respectfully dedicated to their author:
William C. Davis, Jr.
====================
DISCLAIMER
----------
The application described in this documentation, this documentation
itself, and all programs and/or files written or modified by the
application are supplied "as is." Responsibility for determining
its suitability for any purpose rests solely with the user. The au-
thor will NOT be held responsible for injury or damages resulting
from the use of the application; all remedies rest solely with the
user. The application is distributed without any warranties,
express or implied, with these exceptions ONLY: copies of the pro-
gram files distributed on author-supplied disks will be replaced if
the disk(s) prove defective; and, if your copy of the program isn't
operational because of an author error, and you obtained your copy
from the author or an authorised distributor, a complete set of the
program files is available upon request.
+=================================================================+
| LIMITED LICENSE |
| =============== |
| Individual users may make copies of the program files for |
| backup and personal use. Individual users are also encouraged |
| to distribute copies to others, provided that all files are so |
| distributed in their entirety and without modification. |
| Computer clubs may make copies for distribution, with the |
| same provisions, and also provided that no fee in excess of a |
| reasonable copying/media fee is charged. (Reasonable is taken |
| to mean $10.00). Commercial distribution by library companies |
| or individuals wishing to act as distributors is permitted. I |
| would appreciate being asked, first! |
+=================================================================+
+=================================================================+
| QBALL is distributed as user-supported software, ("Shareware"), |
| and should be registered. See Appendix G for registration form. |
+=================================================================+
COPYRIGHT INFORMATION
---------------------
IBM, PC-DOS are trademarks of International Business Machines.
MS-DOS, QuickBASIC, GW-BASIC are copyright, Microsoft, Inc.
BASWIZ is copyright, Thomas G. Hanlin III.
4DOS is copyright, J.P. Software.
---------------------
[ iii -- Exterior Ballistics -- QBALL ]
INTRODUCTION
------------
QBALL is a menu-driven application for the rapid computation of
ballistic values for small arms projectiles. QBALL will quickly com-
pute point-of-impact data, velocity and energy levels, trajectories
relative to line-of-sight, and times of flight. Additional routines
permit the calculation of ballistic coefficients, point-blank range,
wind deflection corrections, sectional densities, impact variations
for non-horizontal fire, and free recoil energy. Printing routines
provide for the production of hard copy where appropriate. Starting
values to which the program will default may be modified using the
built-in configuration routines.
It is assumed that QBALL users will have some knowledge of exter-
ior ballistics. QBALL is not intended as a means of learning the sub-
ject; several of the references in the Bibliography contain basic in-
troductions to ballistics. Study of the references will amply repay
the effort involved.
QBALL uses the "G1" drag function for computation of trajectory
and other values. Appendix D of this documentation compares values
from selected published tables with values calculated using QBALL.
Warning! QBALL users are cautioned that data computed using the
routines contained herein should be used as guides to the determination
of ballistic performance! Should the user be engaged in reloading
small arms ammunition, it is incumbent upon the user to verify the data
obtained using QBALL with a standard published reloading manual. Sev-
eral such manuals are listed in Appendix C.
The application title, "QBALL" does not in any way refer to the
game of billiards; it's short for "Quick BALListics." Seemed appro-
priate, somehow: QBALL's written in QuickBASIC.
If you find QBALL of use, but would like it to do something that
it doesn't do now, or have suggestions to improve what it does already,
you are invited to send in a copy of the Enhancement Form. While no
promises are made that your suggestion will be incorporated, the first
person suggesting an improvement which is subsequently implemented will
receive a free copy of the first release incorporating that improvement.
The latest version of QBALL is available from the author for a
$25.00 registration fee. Registration entitles the user to the latest
version with one free upgrade, and a 3-hole punched printed manual. The
QuickBASIC 4.50 source code is available to registered users for $50.00.
You may register and obtain the source code at the same time for $60.00.
The most current version is also available on the EXEC-PC Bulletin
Board (Modem: 414 789-4210, 8N1, 1200/2400 baud). Last time I looked,
EXEC-PC charged $60 for a year's membership; you may subscribe on-line.
(Free plug: EXEC-PC beats h--l outta CompuServe!) Downloads from any
other source may not include all the necessary files -- caveat emptor.
[ 2 -- Exterior Ballistics -- QBALL ]
1.3 Copying the program files.
-------------------------
It is a good idea to make a copy of the original QBALL files, and
keep it in a safe place. Run QBALL from copies of the original! Make
sure that you copy both QBALL.CFG and QBALL.EXE to the same directory,
or onto the same disk. QBALL.EXE will look for its associated .CFG
file in the current directory. (Running the configuration routine
writes the resulting .CFG file to the current directory.)
If QBALL.CFG is not found, QBALL.EXE will default to its own
internal values, so lacking the .CFG file is not fatal. (Just neater
to put 'em both in the same place!)
Put the documentation files wherever you can get at them.
1.4 Printing the documentation.
--------------------------
The QBALL???.DOC files are formatted to print with a wide-enough
left margin to allow for punching to fit a 3-ring binder. There is no
need to set your printer to print the IBM graphics set as in earlier
editions; this version of the on-disk documentation uses only the low-
order characters. You need not set your printer to skip perforations
in fanfold paper; the document files contain the appropriate form-feed
control characters.
You will be printing 51 pages, but using just 27 sheets; plan the
paper and time requirements accordingly! First, copy "QBALLODD.DOC"
to your using the command
COPY QBALLODD.DOC PRN
When that's done, flip the paper over, and copy "QBALL.EVN" on the re-
verse side of the same sheets, using the command
COPY QBALLEVN.DOC PRN
Now go away and do something else. Each pass takes about 25 min-
utes to print at 10 cpi, near-letter quality. (If you're in a tearing
hurry, print in draft mode...)
[ 4 -- Exterior Ballistics -- QBALL ]
1.6 Starting QBALL
--------------
Log into the directory or onto the disk where you've put
QBALL.EXE and QBALL.CFG, and type:
QBALL (+ [Enter]).
The next thing you'll see is this screen, here somewhat modified
to permit printing it without using graphics characters:
+++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
+=====================================================================+
| +=======+ + + + |
| | | | | | |
| | | | +===+ | | |
| | | +===+ +===+ | | |
| | =+ | | | | | | | |
| +=====|=+ +===+ +===+ + + |
| += Reg #0201SW |
| [ Exterior Ballistics for PC's & Compatibles ] |
| [ Using G1 Drag Functions -- version 2.01] |
| [ Copyright (c) 1992 - Benjamin W. Hartley ] |
+=====================================================================+
Welcome to computer ballistics with QBALL!
QBALL provides small arms trajectory data quickly and accurately.
Users are encouraged to verify QBALL data with a standard reloading
handbook! The author will NOT be responsible for the misuse or misapp-
lication of QBALL-generated data.
===> press any key <===
(-SAV)
++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
QBALL "honked" at you, didn't it? That simply means that QBALL
could not find a specialized *.INI file; it doesn't exist right now,
but you'll be writing one later. If you heard two tones, the opening
screen should also be displaying "(-CFG)," indicating that QBALL.CFG
wasn't found, either, and QBALL started with its internal default
values.
Two pieces of information which you should note from the initial
screen: the Version, and the Registration Number. When you register
your copy of QBALL, please include these numbers on your order.
Press any key to continue.
[ 6 -- Exterior Ballistics -- QBALL ]
The most frequent use for QBALL will be the production of ballis-
tics tables for a specific cartridge/load. With the menu shown on the
screen, pressing "C" will open the menu for computation of ballistic
or gun data. More information about using this option is contained in
Chapter 2.
If you wish to infer a ballistic coefficient, then press "B".
More information is to be found in Chapter 3.
"Use <U>tilities...", "U" provides a means to set display col-
ors, the status of the printer and noise switches, and the values to
which QBALL will default upon start-up. You may also "shell to DOS"
from the utilities menu. See Chapter 5 for more information about
the utilities menu, generally, and configuring QBALL.
"<N>ew or Changed..." goes to a secondary menu which allows entry
or modification of input data. We'll try this one a bit later.
"Quit" -- press "Q" to return to DOS. QBALL will ask you to
confirm that you indeed wish to quit. Press "Y" to return to DOS or
press "N" to continue using QBALL. (If you have saved data to disk
from within QBALL, you will also be prompted:
Retain Saved Data ? ([Y] or N).
The default is "Y" -- that is, keep the saved data. It is STRONGLY
recommended that, in this case, you press "N," at least until you've
played with QBALL a bit.
Back to work...
For right now, press "C" to compute ballistic data and to do the
"tutorial" which follows. Go on to Chapter 2, page 7.
[ 8 -- Exterior Ballistics -- QBALL ]
2.2 Computing and displaying a range table.
--------------------------------------
Assuming everything is going as it's supposed to go, the
screen will clear, and you'll be presented with this screen:
++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
> Ballistic Computations: Typical Firearm <
+=================================+
| *** Computations Menu *** |
| ------------------------------ |
| <S>et/Reset Current Zero Range |
| Range <T>able (0 MUST BE SET) |
| <O>ther Ballistics Procedures |
| <N>ew or Changed Input Data |
| ------------------------------ |
| <ESC> to M A I N M E N U |
+=================================+
---------------------------------------------------------------+
[ MV: 2300 ][ C1: .250 ][ Wt: 125 ][ Met: 59o 0' 29.53" 78% ]|
|
(Note: Info line shown) +---------------------+
( "folded". ) +---------------
[ H: 1.00 ][Yds]
++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
AHA! All the spaces on the Info Line now have values in them,
some of which you just entered, and some of which are the QBALL de-
fault (or starting) values.
"<O>ther Ballistics Procedures" are described in Chapter 5.
As you can see, you can change the Input Data by using option "N"
on this menu; for now, continue with what you've got.
"ESC" will "back up" one menu; try it and see. Then remember to
press "C" to get back here.
The other two options are described in the following section.
(From here on, the Screen Header line, which )
(tells you what cartridge/bullet you're deal-)
(ing with, and the Info Line will be omitted)
( from the printed examples. )
[ 10 -- Exterior Ballistics -- QBALL ]
This table is interpreted as follows: if, for example, a bullet
having the given ballistic characteristics is fired at the given
muzzle velocity, then, at a range of, say, 200 yards, it will retain
1693 FPS velocity, 795 ft-lbs of energy, will have dropped 16.2 inches
below the line of departure, will have risen to a maximum of 1.8"
above the line of sight, will have been blown 7.7" sideways by a 10
MPH crosswind, and will have taken 0.305 seconds to travel 200 yards
downrange from the muzzle. Additionally, the height of the bullet
above or below the sight line in both minutes of arc and inches is
given at each listed range. Note that the tables displays "0.0" at
150 yards, the zero range. In similar fashion, data may be read from
the table for each of the listed ranges.
Should you try this procedure with a larger range, or a smaller
range increment, QBALL will display as many lines as will fit on the
screen, and display a prompt like this:
----------------------> More <-------------------.
Press any key to display the next part of the table.
The hardcopy print routines recompute the tabular data, so there
is no need to be concerned with information which has scrolled off the
screen. Put a marker in this page, and return to it to experiment
later.
Press "Y" to display graphics...(and turn the page).
[ 12 -- Exterior Ballistics -- QBALL ]
Now let's play "what if...?" What would happen to the trajectory
if, say, the muzzle velocity is increased to 2500 FPS? Let's find
out. With the computations menu displayed, press "N" to access the
"New or Changed Input Data" menu, which looks like this:
+=================================+
| *** New Input Data Menu *** |
| ----------------------------- |
| <C>artridge/Bullet Identifier |
| Muzzle <V>elocity |
| <B>allistic Coefficient |
| Bullet <W>eight |
| <M>etro (dFnt 'Alt "Hg %RH) |
| Sight <H>eight |
| Yds/Mets <S>wap (Now Yards) |
| ----------------------------- |
| <ESC> to Computations Menu |
+=================================+
In this instance, press "V" to change the muzzle velocity, and
enter "2500" when prompted. You'll be returned to this menu; it is
possible, but not recommended, to change more than one item of input
data at a time. Note that the info line now reflects the new muzzle
velocity. Press "ESC" to return to the computations menu.
Now step through the process of setting the zero range (150), the
maximum range for the range table (200), and the range increment (25).
When prompted for graphics, press "Y." In addition to the graph,
this should be displayed:
+=========================+
> Current < > Previous < | Graphics Menu |
Max Ht: 1.5" @ 86 +-------------------------+
Min Ht: -3.5" @ 200 | <Q>uit Graphics Routine |
MuzVel: 2500 FPS | <G>rid Toggle |
BCoeff: .250 | <S>ave Current Data |
ZeroRg: 150 Yards | On Disk: <0> |
Metro : Standard +=========================+
Now press "0" (that's "zero") to retrieve the trajectory data you
saved previously. Here's what you should get:
+=========================+
> Current < > Previous < | Graphics Menu |
Max Ht: 1.5" @ 86 1.8" @ 86 +-------------------------+
Min Ht: -3.5" @ 200 -4.5" @ 200 | <Q>uit Graphics Routine |
MuzVel: 2500 FPS 2300 | <G>rid Toggle |
BCoeff: .250 .250 | <S>ave Current Data |
ZeroRg: 150 Yards 150 Yards | On Disk: <0> |
Metro : Standard Standard +=========================+
[ 14 -- Exterior Ballistics -- QBALL ]
At this point, either print the range table, or skip the print,
and return to the computations menu, and we'll take a more detailed
look at the "New or Changed Input Menu."
2.4 Changing Input Data.
-------------------
Here's the "New or Changed Input Menu" again.
+=================================+
| *** New Input Data Menu *** |
| ----------------------------- |
| <C>artridge/Bullet Identifier |
| Muzzle <V>elocity |
| <B>allistic Coefficient |
| Bullet <W>eight |
| <M>etro (dFnt 'Alt "Hg %RH) |
| Sight <H>eight |
| Yds/Mets <S>wap (Now Yards) |
| ----------------------------- |
| <ESC> to Computations Menu |
+=================================+
Let's see what each option does.
Cartridge or Bullet Identifier. This option allows you to change
the designation of the cartridge, bullet, or firearm with which you
are working. Press "C" and enter a string of characters. (If you
press enter at the prompt, it returns "Typical Firearm.") Identifiers
are limited to 40 characters length.
Muzzle Velocity. This, as has been seen, changes the muzzle
velocity to be used. QBALL accepts velocities from 300 FPS to 4500
FPS, inclusive.
Ballistic Coefficient. This allows changing the ballistic coeff-
icient to be used, perhaps reflecting a different bullet or cartridge.
QBALL will accept values greater than zero and less than or equal to
unity (one).
Bullet weight. Allows changing the bullet weight. Acceptable
values are any number greater than zero.
Metro. This one's got four parts; you are required to either
confirm or change each of temperature, gun altitude, barometric pres-
sure, and relative humidity. Pressing "Enter" at each input prompt
uses "standard" metro. Acceptable values are as follows:
a. Temperature : -50 to +125 Fahrenheit.
b. Gun Altitude : -800 to 10000 feet.
c. Barometric Pressure : 25 to 35 inches of mercury.
d. Relative Humidity : 0 to 100 percent.
[ 16 -- Exterior Ballistics -- QBALL ]
Point-Blank Range.
-----------------
The "point-blank range" for any weapon / ammunition combination
may be defined as that range for which the trajectory deviates not
more than a specified amount from the line of sight, either above it
or below it.
Press "P" to access the point-blank range determination routine.
When prompted, enter maximum deviation = 3 (for 3 inches above and
below the line of sight). The screen will look something like this:
+++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
Determination of Point Blank Range
----------------------------------
Maximum Deviation 3
----------------------------------
Trial Zero Range = 512 Yards
+++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
After a pause, during which the trial zero range will change several
times, the following will be displayed:
----------------------------------
Point Blank Zero Range = 179
Maximum Range = 207
----------------------------------
===> press any key <===
When you "press any key" you are returned to the computations menu,
where you will observe that the zero range has been set to 179. You
may now go ahead and develop a range table for this weapon/ammunition
combination, using that computed zero range.
It is recommended that you use a range increment which will give
you trajectory heights at even multiples of 50 yards. If you do so,
you'll know how high to sight in your weapon at, say, 100 yards so as
to be zeroed at 179, thus assuring a maximum deviation of 3 inches
from the line of sight out to 207 yards. (The graphics routine, if
invoked, will draw a horizontal line on the screen at scale 3 inches
above and below the line of sight. These lines will continue to be
displayed until you change the zero range.)
And what does all this do for you? Well, with this "point-blank"
zero, you can hold "dead-on" out to slightly more than 200 yards, and
be assured that the bullet will strike no more than 3 inches high or
low at any point along its path. Beats estimated holdover, don't you
think?
[ 18 -- Exterior Ballistics -- QBALL ]
Slant Angle of Fire.
-------------------
Virtually all firing tables and ballistics computations programs,
QBALL among them, assume that the angle of fire in use is relatively
close to horizontal. It is known, however, that firing "upslope" or
"downslope" will effect the strike of the bullet: it will hit high
relative to point of aim in both cases. How high? Press "A," and
enter a maximum range of 400, a range increment of 100, and a vertical
angle of 25 degrees. The following table will be displayed:
+++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
Hits High for Slant Fire, 25d
Above or Below Horizontal
-----------------------------
Range True Hits
Yards Drop High
----- ----- -----
0 0.00 0.00
100 3.64 0.34
200 16.23 1.52
300 40.99 3.84
400 82.94 7.77
-----------------------------
===> press any key <===
+++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
The table tells you that this weapon / ammunition combination,
fired at a vertical angle of 25 degrees above or below the horizontal,
will hit high by the specified distance for each listed range. The
effect is relatively small for small vertical angles, but can become
great enough to be of real concern, especially at relatively long
ranges and at large vertical angles. Try several examples and see.
(A clear exposition of the geometry of this problem may be found in
the LYMAN Manual, listed in the bibliography.)
Sectional Density.
-----------------
The sectional densities of two or more particular bullets may be
used to compare their relative penetrating power. Sectional density
is defined as the weight of the bullet in pounds divided by the square
of its diameter in inches. Press "S," and enter the bullet diameter
in either inches or millimeters. QBALL assumes that any value you
enter which is greater than "1" is in millimeters, and makes the con-
version to inches. The dimension may be taken as the bore diameter of
the weapon you are considering.
This routine reports the sectional density of the bullet under
consideration. This value is included in the Range Table printed
header, but there is no specific routine to print just this value.
[ 20 -- Exterior Ballistics -- QBALL ]
Chapter 3
---------
Inferring ballistic coefficients
""""""""""""""""""""""""""""""""
From time to time, it may be desired to determine the ballistic
coefficient of a particular bullet, and the available tables do not
include that data.
Select "Infer <B>allistic Coefficient" at the main menu. (You
will be encouraged to read this section of the manual, if you haven't
done so already.) Press "Y" to continue with the routine.
QBALL will ask for several pieces of information: basically, two
ranges, and two velocities. This diagram will help you visualize the
setup.
( + = target locations )
|---[r1]----| ( >>>>>>> = bullet path )
|-----------[r2]----------|
Gun >>>>>>>>+>>>>>>>>>>>>>+>>>>>>>>>>>>>>>>
v@1 v@2
r1 = range, muzzle to first range
r2 = range, muzzle to second range
v@1 = velocity at first range
v@2 = velocity at second range
It is possible for r1 to equal zero; in that case, of course, v@1
would equal the muzzle velocity. (This is the only time that QBALL
will allow you to enter a range of zero; "zero" is the default value
for r1.)
The routine for inferring a ballistic coefficient allows use of
nonstandard metro, should you have developed your own velocity data
from live firing. You may change the metro conditions to be used
before beginning to enter velocity data. The ballistic coefficient
reported, however, is adjusted to standard metro conditions in all
cases.
You may enter as many as ten (10) individual range/velocity
pairs. The average v@1, v@2, and ballistic coefficient are reported.
If r1 is greater than zero, i.e., you are not working with a muzzle
velocity, QBALL reports an inferred muzzle velocity.
Let's work through the process. Refer to the table on page 9,
and either copy the range and velocity figures, or run the range table
routines and produce hard copy. We'll do this twice: once, with r1
set to 0, and once more with r1 set to 25; r2 will be set at 100 in
both cases.
[ 22 -- Exterior Ballistics -- QBALL ]
3.2 Second Run: r1 = 25
-------------------
Enter "first range" = 25 and "second range" = 100. When prompted
for the velocities, enter 2218 and 1982. You should end up with the
following display:
++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
For Round Number 1
First Velocity (Ft/Sec) 2218
Second Velocity (Ft/Sec) 1982
For Standard Atmosphere, C1 = .250
Calculate another Round? ([Y] or N)
[ Lower & Upper Ranges (yards) 25 & 100 ]
++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
Again, press "N;" you don't want to calculate another round. The
center of the screen will clear, and, after a short time for computa-
tions, the following information is displayed:
-----------------------------------------
Average C1 for 1 round = .250
Between Mean Velocities 2218 and 1982
Calculated Muzzle Velocity = 2300
-----------------------------------------
Press "N" to skip printing the table, and return to the main
menu. Again note that the information line shows the calculated
muzzle velocity and the inferred ballistic coefficient. You may now
go on to calculate ballistic data using the values obtained using this
routine; QBALL will continue to use this data until changed.
This may have seemed like an exercise in futility: we did, after
all, know what the ballistic coefficient was in the first place.
Suppose, however, you have a ballistics table from, say, Winchester-
Western, which includes only velocity data? Inferring a ballistic
coefficient based on the published velocity figures will allow you to
make your own "custom" firing table for a particular factory round.
(Most ammunition manufacturers are noticeably reticent when it comes
to some ballistics data.) Additionally, should you be reloading your
own ammunition, and have access to two chronographs, you could make a
custom firing table for your own custom ammunition.
[ 24 -- Exterior Ballistics -- QBALL ]
4.5 Typical Printed Output.
----------------------
QBALL will print a "standard header" and a table title at the top
of each table each time you respond "Y" to the printer prompt. (This
is a change from previous releases of QBALL.) The standard header
looks like this:
======================================================
>>> Ballistic Computations for the Typical Firearm <<<
------------------------------------------------------
Muzzle Velocity = 2300 FPS Ballistic Coefficient = .250
Bullet Weight = 125 Gr Sectional Density = n/a
Temperature = 59 deg F Altitude = 0 Feet
Barometric Pressure = 29.53" Relative Humidity = 78%
------------------------------------------------------
For printed data tables, QBALL recomputes each line of data which
appears or has appeared on the screen, so information which has
scrolled off the screen may be printed. (This might occur, for exam-
ple, if you've used a large range, and a small range increment.) In
most data table cases, the format of the printed output is virtually
identical to the screen display.
And here's the printed output for the "Infer Ballistic Coeffi-
cient" routine, using some of the same data we used in chapter 3:
============================================================
>>> Inferring Ballistic Coefficient for: Typical Firearm <<<
------------------------------------------------------------
Given the following meteorological conditions:
Temperature..........: 59 deg F Barometric Pressure....: 29.53"Hg
Relative Humidity....: 78 % Gun Altitude...........: 0 Feet
Relative Air Density.: 1.000 Relative Sonic Velocity: 1.000
and the number of rounds shown, the ballistic
coefficient (C1) was computed using the veloci-
ties indicated.
----------------------------------------------
Round V1 V2 C1
----- ---- ---- ----
1 2300 1982 .250
----------------------------------------------
Average C1 for 1 round = .250
Between Mean Velocities 2300 and 1982
Calculated Muzzle Velocity = 2300
==============================================
[ 26 -- Exterior Ballistics -- QBALL ]
Press "ESC" to return to the Utilities menu.
5.3 Configuring display colors.
--------------------------
Press "C". A special color configuration screen will appear.
Pressing the appropriate keys will "step" through the available colors
for background ("B"), main body text ("foreground," "F"), Highlighted
text ("highlight," "H"), and for the Title/Info line ("low intensity,"
"L"). When you've found a combination that you like, press "ESC" to
use the display colors you have chosen, and return to the configura-
tion menu. Note that the currently chosen and the default color
values are displayed at the bottom of the color configuration screen.
If you get in a muddle, and want to start over again, press "D" to
return to the default color settings.
5.4 Shell to DOS.
------------
You may find it desirable (or necessary) to "drop to DOS" for
housekeeping purposes. Press "D" to invoke a DOS shell; type "EXIT"
(+ [enter]) to return to QBALL. (Upon EXITing a DOS shell, you'll be
returned to the Utilities menu.)
5.5 Using the values you've set.
---------------------------
Having set the display colors and toggles as you like them, and
<ESC>-ing to the main utilities menu, you may:
<W>rite QBALL.CFG File
If you're sure of the values you've entered, press "W" to write a
new QBALL.CFG file to the current directory. (And remember, if you
change your mind, there's nothing to stop you from running Configur-
ation again.)
If you'd like to use the values for this session only, perhaps to
see how they work out, press "ESC." If you decide later to save your
"temporary" setup, choose "U" from the main menu, then choose "W" immed-
iately from the utilities menu. QBALL doesn't care if there's a delay
between choosing configuration values and writing an *.CFG file; it will
quite cheerfully write a *.CFG file using whatever values are in effect
at the time the "W" option is chosen.
5.5 Some other considerations.
-------------------------
The QBALL.CFG file includes a good bit more information than just
the display colors and toggle status. QBALL.CFG also controls the
starting values for the following:
a. Cartridge/bullet Identifier
b. Meteorological conditions
c. Sight height.
[ 28 -- Exterior Ballistics -- QBALL ]
Some Afterthoughts and Some ~~~~Wrinkles~~~~
""""""""""""""""""""""""""""""""""""""""""""
Afterthoughts.
-------------
I'm not entirely happy with the file-handling routines, but
at least they work. Without further bloating the source code, how-
ever, I don't see how to make them any more bullet-proof. I should
very much like to include a way to reread the QBALLSAV.INI file; this
would be of value to those who use the DOS Shell routine to delete
saved trajectory data files. At present, if you don't quit the cur-
rent session and start all over again, QBALL refuses to recognize that
you haven't run out of available QBALLSAV.0nn numbers. (I'd call 'em
"handles" but for the fact that that's a bit too "techie" for me!)
~~~~Wrinkles~~~~.
----------------
QBALL will run from a floppy disk, albeit S-L-O-O-W-L-Y.
The major bottleneck, of course, is in disk read/write operations.
Two ways around the speed problem are, in order of improvement:
1. Run QBALL from a directory -- preferably its own -- on your
hard disk. You'll find the improvement in speed remarkable, and there
will be no need (generally) to be concerned with running out of room
for QBALLSAV files.
2. If you can afford the room, run QBALL from a RAM disk. At
least 300K to is needed to hold a complete set of QBALL files: *.EXE,
*.CFG, and 16 QBALLSAV.nnn files with their associated *.INI file.
The increase in speed, again, is in file save/retrieve operations, but
there's a side benefit (or hazard, if you prefer): you won't be trou-
bled with old data files. So, here's a thought: use a batch file to
copy QBALL onto your RAM disk, and to save the data back to your source
disk or to a floppy. It might go something like this (assuming that
QBALL is on a disk in drive "A:", and your RAM disk is drive "F:"):
COPY QBALL.EXE F:
COPY QBALL.CFG F:
F:
QBALL
DEL QBALLSAV.INI
COPY QBALLSAV.* A:QBALLOLD.***
A:
Call this batch file "DOQBALL.BAT" or some such. This will work fine
in the absence of a hard drive for those who have but one or two 360K
floppy drives -- the lowest common denominator. (Though come to think
of it, how many folks have an EGA and only floppy drives?)
[ 30 -- Exterior Ballistics -- QBALL ]
CALIBER (or CALIBRE) - Technically, the diameter of the barrel mea-
sured across the lands. In practice, the diameter of the bullet. A
measure of length equal to bore diameter; thus, a "fifty caliber"
barrel would be 50 bore diameters long.
CARTRIDGE - Fixed ammunition, including case, powder, primer, and
bullet, for small arms. See ROUND.
CHAMBER - The breech, or rearmost portion of the barrel, which con-
tains and supports the cartridge prior to, during, and immediately
following firing.
COEFFICIENT OF FORM - A number relating the ballistic efficiency of a
given bullet shape to the shape of the projectile used to calculate
the ballistic table.
C1 - Formula symbol for ballistic coefficient.
CROSS WIND ANGLE - The angle between the wind and line of departure.
Typically tabulated as ninety degrees, or "pure" crosswind with no
range vector. QBALL takes left-to-right wind as positive.
DRIFT - Technically, the distance a bullet will travel horizontally
due to its spin. This effect is usually quite small, amounting to
about 7 inches at 1000 yards for the military M2 Ball (.30-'06) car-
tridge. Often confused with wind deflection. See WIND DEFLECTION.
DEFLECTION - See wind deflection.
DOWNRANGE - Refers to the position of objects in space relative to the
direction of fire; point of aim and point of impact, for example, are
by definition downrange.
DROP - The distance a bullet will fall due to the influence of grav-
ity. Measured from the line of departure, not the line of sight.
ELEVATION - Vertical sight adjustment. Also, the (usually small)
angle between the axis of a firearm's bore and the horizontal.
ENERGY - Here, the kinetic energy of a moving bullet, usually given
in ft-lbs. Equal to one half the mass of the bullet in pounds multi-
plied by the square of the velocity in feet per second.
F.P.S. - Feet per second. A unit of velocity. Also abbreviated as FPS
and Ft/Sec.
FT.-LBS. (Also FtLbs, Ft#) - Foot pounds. A unit of energy equal to
the effort required to lift one pound, one foot.
FORM FACTOR - A multiplier which relates a bullet's shape to that of
the standard projectile used to prepare a particular ballistic table.
[ 32 -- Exterior Ballistics -- QBALL ]
MAXIMUM HEIGHT - The highest vertical distance above the line of sight
reached by a bullet between the muzzle and the point of aim. Some-
times confused with midrange trajectory since it typically occurs
about halfway between the muzzle and the target. Maximum height
is usually somewhat higher and occurs somewhat further downrange than
the midrange trajectory. Also called MAXIMUM ORDINATE.
METALLIC SIGHTS - Sights on a firearm which contain no optical ele-
ments, i.e., glass or glasslike plastic lenses.
MET - An abbreviation for "meter"; also, a super-abbreviation of
"Meteorological Conditions." See METER, METRO, STANDARD MET
METER (also METRE) - A unit of length measure equal to 39.37 inches,
3.28083 feet, or 1.09361 yards.
METRIC - Having reference to length measurements based upon the meter,
its subdivisions, or its multiples.
METRO - Short for Meteorological Conditions; the air temperature, bar-
ometric pressure, gun altitude, and relative humidity existing at the
place and time of firing. See STANDARD MET.
MIDRANGE TRAJECTORY - The height of the trajectory at a point halfway
between the firearm's muzzle and the point of aim.
M.O.A. - Minute of Arc. Equal to 1/60 of an angular degree. At 100
yards, 1 M.O.A. is approximately 1.047 inches.
MUZZLE - The foremost point of a firearm's barrel; that part of a
firearm closest to the target.
MUZZLE ENERGY - Foot-pounds of energy developed by a moving projectile
at the firearm's muzzle.
MUZZLE VELOCITY - The speed of a projectile at the firearm's muzzle,
generally expressed in FPS.
N.R.A - National Rifle Association. If you shoot, you SHOULD belong to
this organization.
OGIVE - The curve of a bullet's forward portion. Also, the radius of
this curve, usually expressed in calibers.
POINT-BLANK RANGE - That range for which the bullet's path varies from
the line of sight by no more than a specified amount for the entire
trajectory from the muzzle to that range.
POINT OF AIM - That downrange point with which a firearm's sights are
aligned.
POINT OF IMPACT - That point which a bullet actually strikes. In most
cases, considered in relation to point of aim.
[ 34 -- Exterior Ballistics -- QBALL ]
TARGETED RANGE - That distance furthest from the muzzle where the path
of the bullet crosses the line of sight. (The "sighting in" distance.)
TIME OF FLIGHT - The time necessary for a bullet to travel from the
muzzle of a firearm to a given range.
TRAJECTORY - The path of a moving projectile. Often expressed as the
number of inches above or below the line of sight.
WINDAGE - Horizontal, lateral sight adjustment. Also, the sight
adjustment required to compensate for crosswind effects at a given
range.
WIND DEFLECTION - The amount of a projectile's horizontal lateral
motion attributable to the action of the wind. Often mistakenly
called drift. See DRIFT, WINDAGE
YAW - Normally, a situation in which a bullet rotates on its axis at a
small angle to the line of flight.
ZERO - The sight setting at which point of impact and point of aim
coincide at a given range. Also, the process of determining that
sight setting. See also SIGHTING IN.
[ 36 -- Exterior Ballistics -- QBALL ]
Suppose you have determined a ballistic coefficient from pub-
lished data, say, the Ballistics Section of "Gun Digest." Having the
ballistic coefficient, use that figure to calculate a table showing
the same data as the published table. If, for example, the resulting
velocities are too high, then reduce the ballistic coefficient that
you're using to, say, 90% of the value QBALL has reported. Recompute
the table. If the resulting velocities are now low relative to the
published data, increase the second ballistic coefficient to 95% of
the value originally used. In similar fashion, continue to refine
the value of ballistic coefficient until the QBALL results agree as
closely as possible with the published data.
In general, however, the process of successively refining a ball-
istic coefficient will prove unnecessary. The very small variations
introduced by differences between successive bullets in a string,
variations in muzzle velocity, and, possibly, rapidly changing metro
render the process of successive refinement superfluous.
[ 38 -- Exterior Ballistics -- QBALL ]
H O U S E K E E P I N G
- - - - - - - - - - - -
It is STRONGLY recommended that you respond "N" to the "Retain
Saved Data Files" prompt, which is displayed after you confirm quit-
ing QBALL. This is the cleanest technique, and doesn't require any
further action on your part. If, however, you're a glutton for pun-
ishment, there are two ways of going about this, both from the DOS
prompt.
First, you could enter:
DEL QBALLSAV.*
This is the simplest way, and avoids confusing QBALL in a later ses-
sion. This, however, is exactly what the "N" response does.
Second, and if you want to keep the trajectory data for later
examination, enter this (or use a batch file):
DEL QBALLSAV.INI
and
REN QBALLSAV.* QBALLOLD.*
This preserves the data and gets rid of QBALLSAV.INI, but the current
directory or the current disk may end up jammed with old data.
One further hint: EACH QBALLSAV.00n file uses 5600 bytes of disk
space, and the .INI file uses 5 bytes. That's a LOT of disk sectors;
make sure you've got sufficient space in the current directory/on the
current disk for better than 90K worth of files! QBALL will detect a
"disk full" error, but why take the chance?
[ 40 -- Exterior Ballistics -- QBALL ]
Appendix E
----------
Error analysis
""""""""""""""
How accurate are the results obtained with QBALL?
Results from several QBALL runs were compared with comparable
data from two sets of published tables: the Speer Reloading Manual #11
and the Hornady Handbook of Cartridge Reloading, 3d edition. Two ques-
tions were to be answered: first, how well do velocity figures compare
between the three sources?; second, are the trajectories found by the
different sources comparable?
Some difficulty was experienced in the choice of ballistic coeff-
icients and velocities due to the differences between the two pub-
lished sources. Speer, for example, rounds all ballistic coefficients
to two decimal places, while Hornady carries three. In addition, when
comparable values of ballistic coefficients could be found, the Horn-
ady tables quite often did not have the spread of velocities available
in the Speer manual.
The following table summarizes as-comparable-as-possible data
from all three sources. While severely limited, the data shows that
the results obtained from QBALL are in substantial agreement with the
two published sources.
+----------------------------------------------------------------+
| Remaining Velocity, Conditions as Shown |
| ======================================= |
| [ Range = 200 yards, Standard Met ] |
+----------------------------------------------------------------+
| MuzVel = 2100 MuzVel = 2500 MuzVel = 3300 |
| C1 = .12 C1 = .26 C1 = .50 |
| --------------- --------------- --------------- |
| |
| QBALL 1112 1879 2899 |
| SPEER 1102 1872 2895 |
| HORNADY 1126 1875 2892 |
| |
+----------------------------------------------------------------+
(Key: MuzVel = Muzzle Velocity C1 = Ballistic Coefficient)
Table D1. Remaining Velocities With Given Inputs. Note
should be made that the Hornady ballistic coefficients
were actually .122, .259, and .496 for the three sets of
data shown. This accounts for the apparent "high-on-low"
spread of values seen here. QBALL was run with the bal-
listic coefficients as shown.
[ 42 -- Exterior Ballistics -- QBALL ]
A close examination of the data in Table D2 shows that there is
very close agreement between the QBALL results and the published data.
The greatest variation is at the greatest ranges; this is to be ex-
pected. Since the ballistic coefficients used in obtaining data from
the Hornady tables are not exactly those chosen as typical, being
"high-on-low" respectively, it is also expected that the resulting
bullet strikes will be too small, "on", and too large. There is, how-
ever, substantial agreement between the QBALL results and the data
from both published tables. The actual bullet strike differences be-
tween QBALL's results and the published tabular data is two or three
tenths of an inch. This indicates that QBALL is capable of excellent
practical accuracy.
(One and one half inches at 400 yards)
(is equal to three-eighths minutes-of-)
(arc -- that's 22 1/2 SECONDS of arc!!)
(If your rifle will group as tight as)
(this -- let alone tighter -- you have)
(an exceptional rifle, indeed! )
[ 44 -- Exterior Ballistics -- QBALL ]
Error Messages (continued)
--------------
+-----------------------------------+
| Enter -50 <= Temperature <= +125 |
+-----------------------------------+
Attempting to enter a temperature value which is out of
range. (In metro data entry, [enter] inputs the STANDARD
met value: 59 deg F.) (If you really need this program
to operate at Arctic/Saharan temperatures, let me know!
I'll customize one for you.)
+--------------------------------------+
| Enter 0 <= Relative Humidity <= 100 |
+--------------------------------------+
Attempting to enter a relative humidity value which is out
of range. (In metro data entry, [enter] inputs the STANDARD
met value: 78%.)
+--------------------------------------+
| Enter 25 < Barometric Pressure < 35 |
+--------------------------------------+
Attempting to enter a barometric pressure value which is out
of range. (In metro data entry, [enter] inputs the STANDARD
met value: 29.53" Hg.)
+------------------------------------+
| Enter -800 < Gun Altitude < 10000 |
+------------------------------------+
Attempting to enter a gun altitude value which is out of range.
(In metro data entry, [enter] inputs the STANDARD met value:
0 feet - sea level.)
+---------------------------------+
| Enter 0 < Bullet Weight < 1000 |
+---------------------------------+
You're attempting to enter a zero bullet weight, (Huh?), or a
weight better suited to artillery. (1000 gr = 2.3 OUNCES)
+-------------------------------------+
| Enter -2.0 <= Sight Height <= +5.0 |
+-------------------------------------+
You're attempting to enter a value which is out of range.
+------------------------------------------+
| Enter Second Velocity < First Velocity |
+------------------------------------------+
In inferring ballistic coefficients, attempting to enter a
downrange velocity which is larger than the velocity closer
to the muzzle. (Rocket-assisted bullet, maybe?)
[ 46 -- Exterior Ballistics -- QBALL ]
Error Messages (continued)
--------------
+----------------------------+
| Enter Range <= 1760 Yards |
+----------------------------+
+-----------------------------+
| Enter Range <= 1609 Meters |
+-----------------------------+
In both cases, attempting to enter a range outside QBALL's
ability to use effectively. (1760 yds = 1609 met = 1 MILE.
Contact the author if you really need greater ranges.)
+--------------------------+
| Printer does not respond |
+--------------------------+
Your printer is off, or off-line. This message does NOT
appear if you're simply out of paper.
+----------------+
| File not Found |
+----------------+
You're trying to retrieve a file which QBALL thinks exists,
but really doesn't. The QBALLSAV.INI file is probably corrupt
or absent. Quit QBALL, erasing the QBALLSAV.* files as you do
so and restart QBALL.
+-----------+
| Disk Full |
+-----------+
There is insufficient disk space on the default drive's disk
to write the desired QBALLSAV.nnn file. Either: delete some
files, or copy QBALL to a fresh disk and start over. (If this
error occurs, QBALL does a "fix-up" of QBALLSAV.INI, and dis-
ables "<S>ave Current Data.")
[ 48 -- Exterior Ballistics -- QBALL ]
---------
N O T E S
---------
[ 50 -- Exterior Ballistics -- QBALL ]
The following comments wouldn't fit on the other side!
------------------------------------------------------