MADE IN USA

Gadsden Ballistic Calculator

469 factory loads verified against JBM. Zero guesswork.

A 3-DOF solver verified against JBM Ballistics. < 0.02% mean error, 100% pass rate. Full solutions offline, no signal required. No accounts, no tracking, and we never take your data.

Gadsden Ballistics range card showing elevation and windage holds by distance
◉ ACCURACY & SOLVER VERIFICATION

The proof.
And the physics that produce it.

469
FACTORY LOADS VERIFIED
115
CALIBERS
< 0.02%
MEAN VELOCITY ERROR
100%
PASS RATE
0.42%
WORST SINGLE POINT
29,000+
DATA POINTS COMPARED
◉ WHAT < 0.02% LOOKS LIKE AT 1,000 YARDS
6.5 Creedmoor: 140gr Hornady ELD-M, G7 BC 0.315, 2710 fps MV
REMAINING VELOCITY
JBM1,448.62 fps
GADSDEN1,448.58 fps
DELTA0.04 fps
BULLET DROP
JBM-325.58"
GADSDEN-325.63"
DELTA0.05"
TIME OF FLIGHT
JBM1.5148 sec
GADSDEN1.5150 sec
DELTA0.2 ms
These numbers hold at sea level or 14,000 feet, in 130°F heat or -40°F cold, dead calm or 40 mph crosswind.
◉ THE PHYSICS BEHIND THE ACCURACY

3-DOF Point-Mass Solver

Sub-millisecond trajectory integration from muzzle to target. Professional-grade solver used by competitive and tactical shooters.

G1 & G7 Drag Models

Smooth, artifact-free drag calculation through the transonic region where most solvers break down.

Multi-BC Velocity Bands

Banded BCs step with bullet velocity, tracking published manufacturer data as the round slows.

Standard Atmosphere Model

Full atmosphere from sea level through the tropopause. Density altitude and pressure altitude for any shooting location.

Zero-Day vs Firing-Day

Separate atmosphere for zero and current conditions. Cold bore zero holds when you change altitude.

Powder Temperature Compensation

Muzzle velocity adjusts to the day's temperature from your load's sensitivity and baseline. Summer dope holds in winter.

Coriolis & Earth Rotation

Horizontal and vertical deflection from GPS latitude and compass heading. Matters at 1,000+ yards.

Spin Drift

Spin drift correction for left-hand and right-hand twist barrels.

Aerodynamic Jump

Optional vertical crosswind correction most solvers ignore. Twist-direction aware.

Barrel-Length MV Correction

Barrel-length velocity correction for 113 calibers with SAAMI reference barrel lengths.

Suppressor Modeling

MV offset for 49 calibers (baffled and flow-through). Automatic POI shift correction.

MV & BC Truing

Match your solver to real-world impacts at known range. Trued values persist and override in all future solves.

Shooting Angle Compensation

Rifleman's rule with corrected range and gravity for uphill/downhill shots.

Real-Time Weather

GPS-based atmospheric data. Phone barometer for local station pressure. Live weather pulled automatically.

Wind Clock System

Full 12-position clock. Compass-relative conversion when heading is captured.

◉ VERIFIED ACROSS EVERY CATEGORY
CATEGORY
LOADS
MEAN ERROR
WORST ERROR
All loads469< 0.02%0.42%
Rifle384< 0.01%0.42%
Handgun43< 0.06%< 0.07%
Rimfire30< 0.09%n/a
Shotgun slug12< 0.09%n/a
G7 drag model211< 0.01%< 0.01%
G1 drag model258< 0.03%0.42%
469 of 481 catalog loads produce enough trajectory points for JBM comparison. All 481 are in the app.
◉ TESTED EVERYWHERE YOU SHOOT
TEMPERATURE-40°F to +130°F
ALTITUDESea level to 14,000 ft
HUMIDITY0% to 100%
WIND SPEED0 mph to 40 mph
WIND DIRECTION12 bearings to full circle
PRESSURE27.50" Hg to 31.00" Hg
136 Simulated Locations · Every Continent
Camp Perry, Ohio
Whittington Center, New Mexico
Death Valley
Swiss Alps
Namibia
Mongolia
Patagonia
Antarctica
◉ METHODOLOGY
Every factory load in the catalog was submitted to JBM Ballistics' public trajectory calculator and compared to our solver at every 100-yard step, under standard atmosphere and a committed set of environmental conditions. Pass criteria: average velocity error below 0.5%, maximum single-point error below 1.0%. Every scenario passes with substantial margin. Worst category average is below 0.09%. Every solver change is verified against the full test suite before release.
◉ PRIVACY

We Never Take Your Data.
Period.

WHAT WE DON'T DO
✕No analytics or telemetry
✕No crash reporting
✕No advertising identifiers (IDFA, IDFV, Android Ad ID)
✕No user accounts, emails, or passwords
✕No cloud accounts, servers, or sync of ours
✕No background location
✕No camera, microphone, contacts, photos, or health data
✕No cookies or web tracking
✕No push notifications
WHAT WE DO
GPS location
Only when you tap "Fetch Weather": ephemeral, never stored, sent only to Open-Meteo
Optional feedback form
Only if you send one: your message, device model, OS and app version, language, screen size, timestamp, plus a screenshot or reply email only if you add them
Local storage
All profiles, dope cards, and settings stored locally in your app sandbox
Your own device backup
Your armory rides along in your iCloud or Google backup so a new phone restores it: your account, not ours. We have no access to it
Two network endpoints.
Weather data from Open-Meteo and an optional feedback form. Nothing else is ever sent to us, and neither one is required to compute a solution.
Full privacy policy →
◉ CATALOGS

481 Factory Loads. Ready to Shoot.

481
Factory Ammo Loads
28 manufacturers
253
Calibers
115 with factory ammo
236
Scopes
28 manufacturers
229
Mounts
23 manufacturers
AMMUNITION28 BRANDS
AguilaAlpha MunitionsBarnesBarrettBergerBlack HillsCCICheyTacEleyFederalHornadyLapuaNormaNoslerPeterson CartridgePPURemingtonRWSSakoSBR AmmunitionSellier & BellotSierraSig SauerSKSpeerWeatherbyWinchesterWolf
OPTICS28 BRANDS
AthlonBurrisBushnellElcanElement OpticsHawkeHensoldtIOR ValdadaKahlesLeupoldMarchMavenMeoptaMinoxNightforcePrimary ArmsSchmidt & BenderSig SauerSteinerSwampfoxSwarovskiTangent ThetaTractTrijiconUS OpticsVortexZeissZero Compromise
MOUNTS23 BRANDS
ADMAero PrecisionArea 419Badger OrdnanceBobroERA-TACGeisseleHawkins PrecisionKnight's ArmamentLaRueLeupoldMDTMasterpiece ArmsMidwest IndustriesNightforceReptiliaScalarworksSeekinsSpuhrTPSUnity TacticalVortexWarne
113
calibers with barrel-length MV correction and SAAMI reference lengths
49
calibers with suppressor MV offset data (baffled and flow-through)
98
caliber twist profiles for default twist rate suggestions
Pull a factory load, select your scope and mount, build a complete profile in under a minute. Pre-validated BC, MV, and turret data.
◉ SEE IT IN ACTION

Every screen earns its place.

Gadsden Ballistics solver with live weather
Solver
Full ballistic solution with live atmospherics.
Gadsden Ballistics rifle and scope armory
Armory
Rifle, scope, ammo: every field that drives the solve.
Gadsden Ballistics rifle armory
Rifles
Every rifle profile, zero, and scope in one armory.
Gadsden Ballistics ammunition armory
Ammunition
Factory loads and handloads, ready to solve.
Gadsden Ballistics range card
Range Card
Full dope card with holds, wind, velocity, and TOF out to 1,600 yards.
Gadsden Ballistics factory ammo catalog
Factory Catalog
481 loads across 28 manufacturers, ready to import.
◉ VERIFICATION TRANSPARENCY

We Publish the
Verification Data.

Most apps ask you to trust the math on faith. We prove it.

WHAT GADSDEN PUBLISHES
VALUE
Factory loads verified vs JBM
469
Calibers covered
115
Worst single-point velocity error
0.42%
Mean velocity error
< 0.02%
Pass rate
100%
Individual data points compared
29,000+
Verification methodology
Published and reproducible
Analytics / tracking
None, by design
User accounts required
No
Data leaving device
Weather (ephemeral) + optional feedback only
Accurate. Private. Published.
◉ PRICING

One Price. Everything Unlocked. Forever.

FREE
$0
•3 rifle profiles
•5 ammo loads
•10 catalog imports
•Max range 1,000 yards
•G1 & G7 drag models
•Coriolis, spin drift & angle compensation
•Powder temp, aerodynamic jump & multi-BC
•All 12 wind positions
•Live weather & MV truing
•Dark + Daylight themes
PRO
$9.99 one-time
✓Unlimited profiles, loads & imports
✓Extended range to 3,000 yards
✓BC truing
✓PDF/CSV export
✓25 & 50 yard fine steps
✓All 5 themes
No subscriptions. No renewals. No ads. Pay once, own it forever.
One-time because this is a one-person shop, not a subscription company.

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