BIG BALLISTICS
(v1.00 - 7 Feb 2020)

(Page created 7 February 2020)

NOTE: This is called "Big" because it supports 'extreme' use cases such as 16-inch naval rifles. Virtually all online ballistics calculators are designed only to work with small arms use-cases.

The program source is based off an AppleBASIC program written in 1983 by W.J. Jurens and published in Warships International #1 (1984). It was rewritten into Python in 2018, and then into Javascript in 2020.

CLICK HERE FOR BACKGROUND ON ORIGINAL PROGRAM

NOTE: If you are using very short integration intervals AND simulating long trajectories, such as battleship guns at 30-45 degrees, with flight times of 60+ seconds, your browser may seem to hang. Just wait and it'll eventually cough out a table.

NOTE II: The code for the program is contained entirely within this HTML file; so you can download it for offline use on your own PC, or to extend/edit it yourself, without having to worry about tracking down dependencies from elsewhere.

Select Atmospheric Model:

Vacuum
U.S. Pre-1945 Atmosphere (Jurens Model)
British Standard Atmosphere (Jurens Model)
ICAO Standard Atmosphere 1964 (Jurens Model)
US Standard Atmosphere 1976 (Good to 86 km)

Select Gravity Model:

Simplified Lunar Gravity
Simplified Mars Gravity
Simplified Earth Gravity
Simplified Earth Gravity (Jurens Model)
US 1976 Standard Atmosphere Gravity Model

PRE-GENERATED TEMPLATES

these buttons are matched against known range tables to generate 99% valid form factors.
these buttons contain reasonable assumptions, i.e. no firing table is known, but we assume that the shell form factor is similar to other smaller/larger caliber shells of the same design (example: Panzergranate 39).
these buttons have valid basic properties (diameter, mass, muzzle velocity), but the drag factor and form factor are completely generic.
these buttons are missing one (or more) validated basic properties and the drag factor and form factor are completely generic.

SMALL ARMS / MACHINE GUNS

UK
US
GERMANY

USSR

TANK GUNS

US



UK






German
Modern Weapons

ANTI-AIRCRAFT / DUAL PURPOSE GUNS

HEAVY GUNS

NAVAL GUNS






AERIAL BOMBS

WW2 Bombs


1960s Mk 80 Series Bombs

MANUAL DATA INPUT

Yellow boxes are secondary input fields; enter your data and hit enter, and they will automatically translate/convert into the primary input fields.

: Projectile Diameter (mm)
: Inches/Caliber (Proj. Diam.)
: Centimeters (Proj. Diam.)

: Projectile Mass (kg)
: Pounds (Proj. Mass)
: Grains (Proj. Mass)
: Grams (Proj. Mass)
 WEAPON SCALER

This will calculate scaled masses for a larger or smaller shell of the same general shape. To use, you first load a hypothetical shell into the left-side panel, and then enter the new caliber you want to scale it to. Currently, it only works with millimeters and kilograms in the left-side.

: Scaled up Proj. Diam (mm)
: Scaled Proj. Diam (inches)
: Scaled Proj. Mass (kg)

Clicking on the button will automatically copy the new scaled variables over to the calculator on the left-hand side.

: Projectile Inital Velocity (m/sec)
: ft/sec (Proj. Vel.)
: MPH (Proj. Vel.)
: km/hr (Proj. Vel.)
Common Initial Velocities

B-17 Combat Speed - 220 MPH TAS @ 25,000 ft
B-29 Combat Speed - 320 MPH TAS @ 31,600 ft
SBD Dauntless Max. Dive Speed - 278~ MPH TAS
Ju-87 Stuka Max. Dive Speed - 350 MPH TAS
385 m/sec (75mm KwK 37 L24 APCBC on StuG / Pz IV)
790 m/sec (76mm M1 Gun on Sherman)
935 m/sec (75mm KwK 42 L70 APCBC on Panther)

NOTE: Heavy Bombers of WW2 rated at 89% of top speeds in Standard Aircraft Characteristics due to formation keeping needs.

: Projectile Angle of Departure (degrees)
: NATO Mils (Proj. Angle of Departure)
: Soviet Mils (Proj. Angle of Departure)
Common Angles of Fire/Drop

45° -- Maximum Ballistic Range
0° -- Level Bombardment/Zero Elevation
-45° -- Ju-88/TBF Shallow Dive
-80° -- Ju-87/SBD Steep Dive
-3° to 13.5° -- 12" Guns on HMS Dreadnought
-5° to 15° -- 57mm Anti-Tank Gun
-12° to 25° -- 75mm Gun in M4A1 Sherman

: Projectile Fire/Drop Altitude (m)
: Proj. Fire/Drop Altitude (feet)

: Target Altitude (m)
: Proj. Target Altitude (feet)
Common Target/Drop Altitudes

0.85m -- Chest height of average White Tailed Deer.
1.30m -- Chest height of average 1.74m tall man.
1.41m -- Turret Ring Height of Pz V Panther.
1.98m -- C1 Ariete MBT Gun Barrel Centerline.
2.13m -- Deck Height of US WWII Fleet Destroyer.
2.20m -- Panther/Tiger I Gun Barrel Centerline.
7.31m -- Armor Deck Height of Iowa-Class BB.
15.84m -- Flight Deck Height of Essex-Class CV.
487m (1,600ft) - Ju-87 Bomb/Pullout Altitude
600m -- Accepted Height of Burst for Hiroshima Bomb.
6,705m (22,000ft) - B-17/24 Bombing Altitude
10,058m (35,000ft) - B-29 Bombing Altitude
15,240m (50,000ft) - B-36/52 Bombing Altitude
24,384m (80,000ft) - SR-71/B-70 Bombing Altitude
: Projectile Form Factor

G1 (Ingalls)
G2 (Common in Autocannon)
G5
G6 (Spitzer Bullet)
G7
G8
GL (1880's Rifles)
 PROJECTILE DRAG MODEL SELECTION
G1 (Mach 0 to 9) (Validated to Mach 5)
G2 (Mach 0 to 9) (Validated to Mach 5)
G5 (Mach 0 to 9) (Validated to Mach 5)
G6 (Mach 0 to 9) (Validated to Mach 5)
G7 (Mach 0 to 9) (Validated to Mach 5)
G8 (Mach 0 to 9) (Validated to Mach 5)
GS (Sphere) (Mach 0 to 9) (Validated to Mach 5)
GL (Mach 0 to 9) (Validated in Mach 0.35 to 3.22 range)
KD (Arrow) (Mach 0 to 3.987)
M829 APFSDS (Mach 0 to 9) (Validated to Mach 5.4)
Mk 83 1000 lb Low Drag Bomb (Mach 0 to 5)
AN-M64 500 lb Hi Drag Bomb (Mach 0 to 5)
Paris Gun 1918 Shell 'H' (Mach 0 to 9)

: Integration Interval (seconds): The smaller the number, the more accurate the table will be, but it will take longer to generate it.

Time of Flight: In the 1930s-40s, shipboard gunners with water cooled .50 MGs were trained to fire continuously to walk tracers onto target and the practical range for said weapons was given as approximately 1,400m; or about 4.25 seconds of flight at a 45 degree angle. 		BALLISTIC EVALUATION MODEL:
Ballistic Trajectory Evaluation
Ballistic Range Evaluation(m) (yds)
Anti-Aircraft Evaluation Proj. TOF (secs.)
Form Factor Finder Known Range (m)

The Form Finder works by entering a known maximum range in the box above for a specific firing angle. It then runs trajectories over and over, slowly iterating the form factor until an acceptable one is found. It repeats this for all form factors.

WARNING! This is very slow!

Output Summary

Detailed Output