The same field manual that ships inside the app, how to use it, what the words mean, and the habits that put rounds on steel.
HOW TO USE THE APP
Ballistics tab → + → pick a cartridge from the library (it arrives with typical twist, zero, and factory loads) or start blank. Open Edit Gun Profile and set sight height, twist, barrel length, and zero range to match your rifle. For best accuracy, also record the ammo you zeroed with (name, drag model, BC, velocity) in the Zeroed with section: every other load's dial is then computed relative to your scope's actual zero.
Library velocities come from factory test barrels. Chronograph your load if you can, or shoot a known distance and let True Velocity (in the ammo editor) solve it from your observed drop. Muzzle velocity is the single most influential input.
Environment tab → Capture Live fills pressure, temperature, humidity, and location; check every value it fetched. For a steep shot, tap the camera icon and sight along the phone to capture incline.
On Solution: drag the slider, tap ±10/±100, or tap the big number to type an exact range. Set the wind with the clock dial: drag the arrow to where the wind comes from.
ELEV is your dial-up; WIND is your hold with direction spelled out. On a Holdover gun the same numbers arrive as real inches or feet at the target. The row below shows velocity, energy, time of flight, and Mach; teal or indigo Mach means transonic caution.
Impacts consistently high or low at distance? Ballistics tab → your load → True Velocity. Enter the range you shot, whether the group landed low or high, and the miss in MIL, MOA, or inches, then Apply the solved velocity to the load. Your whole D.O.P.E. table snaps to your actual barrel.
Tap the share icon → Save to Photos for an offline D.O.P.E. card, or Share… to AirDrop it to a spotter. On the watch, long press the solution page to share a card straight from your wrist. Cards stamp their conditions and time, so you'll know when they're stale.
Settings → Range Journal → +. AimCalc snapshots the moment: profile, range, solution, conditions, and location. You add a photo of the target and your notes. Entries read newest-first, like a shooter's diary that builds itself.
Tap the target icon on Solution to save named targets (range + incline). Engage one with a tap, and on the Apple Watch, tap the chevrons or swipe the target bar to flip between them, crown to fine-tune.
The watch companion syncs every profile and your conditions automatically, then solves on-device: tap the profile name to switch guns, crown changes range, the wind page sets speed and direction and shows the air the solution flies in. It keeps working with the phone in your pack.
THE SOLUTION
An angle equal to 1/1000 of a radian. One MIL spans about 3.6 inches at 100 yards, or exactly 10 cm at 100 m, which is why metric shooters love it. Most tactical scopes adjust in 0.1 MIL clicks.
1/60 of a degree, about 1.047 inches at 100 yards. Common on American hunting scopes, usually in 1/4 MOA clicks. 1 MIL ≈ 3.44 MOA. Neither unit is better; use whatever your turrets speak.
Fixed sights and red dots can't dial a correction, so you aim off instead, a real-world offset at the target. Set a gun's corrections to Holdover and AimCalc speaks inches or centimeters, switching to feet or meters when holds get big (50.7 in reads as 4.22′). Handgun presets arrive in holdover automatically; any gun can switch.
The vertical correction to dial or hold so the bullet lands on target at the dialed range. "2.8 MIL Up" means come up 2.8 milliradians from your zero.
The horizontal correction for wind drift, spin drift, and Coriolis combined. AimCalc shows the hold direction: "0.6 MIL Right" means hold right because the bullet is drifting left.
"Data On Previous Engagements", your proven come-ups by range. The D.O.P.E. save button turns the current solution into a photo card you can reference with the phone in airplane mode or print for your stock.
The distance where your sight line and bullet path intersect and your turrets read zero. AimCalc stores the atmosphere from the day you zeroed, so solutions stay honest when you travel to different altitude or weather.
Vertical distance from bore centerline to the middle of your scope. It's why holds get huge up close: at 5 yards the bullet is still riding almost a full sight-height below where you're aiming.
Saved firing points: name, range, incline, and azimuth. Build the list at the stage walkthrough (target icon on Solution), then engage plates with a tap, or swipe between them on the watch. Manually changing range disengages the target, since your D.O.P.E. no longer matches it.
A session log that captures the whole moment in one tap: the active profile, range, the solution in that gun's own correction style, full conditions, location, and the engaged target, plus your target photo and notes. Browse it newest-first in Settings → Range Journal. The photo of your group next to the solution you dialed is how D.O.P.E. becomes knowledge.
AimCalc on Apple Watch runs the same solver on-device. The phone syncs every profile, your environment, and the target list automatically; the watch owns range (Digital Crown), wind, and its own profile choice, and can share a D.O.P.E. card with a long press. Last sync persists, so it solves with the phone out of reach.
BULLETS & BALLISTICS
How well a bullet resists drag compared to a standard reference shape; higher is slipperier. A BC only means something paired with its drag model: G7 0.326 and G1 0.646 can describe the same bullet.
Two reference projectile shapes. G1 fits flat-base and older bullet designs; G7 fits modern long boat-tail match bullets and stays truer at long range. Use whichever BC your bullet maker publishes: never mix a G1 number into a G7 field.
Bullet speed leaving your barrel. The single most influential input you control. Factory numbers come from test barrels, a shorter barrel gives up real speed, so chronograph your rifle or true the velocity against observed drops.
As a bullet slows toward the speed of sound (Mach 1.2 down to 1.0) drag spikes and some bullets lose stability and accuracy. AimCalc shades this band teal on charts and colors Mach readouts; treat solutions past it with field verification.
Gyroscopic drift in the direction of your rifling twist, a right-twist barrel walks shots a few tenths of a MIL right by 1,000 yards. AimCalc includes it automatically using your twist rate and bullet dimensions.
The Earth rotates under the bullet during flight. It's tiny (a tenth or two of a MIL at 1,000 yards) and only matters at long range. Enter latitude and azimuth of fire on the Environment page to include it.
Solving your real muzzle velocity from observed impacts instead of trusting the box. Shoot a measured distance, enter how far the group landed high or low (ammo editor → True Velocity), and AimCalc computes the velocity your barrel actually delivers, then applies it to the load with one tap.
"1:8" means the rifling turns the bullet one revolution per 8 inches. Long heavy bullets need fast twists to stabilize. The engine computes a Miller stability factor; presets ship with each cartridge's typical twist.
Your scope has one mechanical zero, and it belongs to the specific load you zeroed with. Record that load's BC and velocity in Edit Gun Profile and AimCalc solves the scope angle from it, so every other load dials honestly relative to your real zero. Field-proven in .22 LR, where one 50 yd zero can serve everything from 710 to 1470 fps ammo; leave it blank if you re-zero for each load.
Nothing in AimCalc is guesswork or reverse-engineered: the point-mass equations of motion follow McCoy's Modern Exterior Ballistics, drag uses the public G1/G7 standard tables from the U.S. Army's Ballistic Research Laboratory, spin drift is Bryan Litz's published formula with Don Miller's stability rule, and the atmosphere is the ICAO standard with the Buck humidity correction. These are open scientific publications, the same math behind every serious solver, implemented independently.
READING THE ENVIRONMENT
The absolute air pressure at your location, what a Kestrel reads, and what AimCalc wants. It is NOT the sea-level-corrected number in weather reports; at 5,000 ft they differ by about 5 inHg.
One number that rolls pressure, temperature, and humidity into "how thick is this air." Higher DA = thinner air = flatter shooting. Two days with the same DA shoot the same, which makes it a great sanity check between apps and shooters.
Wind from 3 or 9 o'clock is "full value": all of it pushes the bullet sideways. From 1:30, 4:30, 7:30, or 10:30 it's roughly 70%. From 12 or 6 it barely drifts the bullet at all. The dial handles the math; you supply the honest call.
Shooting steeply up or down hill drops less than the same distance level, because gravity works across less of the bullet's path. Enter the angle on the Environment page; AimCalc does the full vector math, not the old rifleman's-rule shortcut.
FIELD TIPS