Is this calculator affiliated with Nikon Spot-On?

No. Optics Intel is not affiliated with Nikon. This independent tool accepts generic G1 and G7 ballistic coefficients and custom MOA or MIL reticle marks.

Can a calculated trajectory replace range verification?

No. Chronograph the actual firearm when possible, confirm the zero and every intended hold with live fire, and treat calculated results as a starting prediction.

Full exterior-ballistics model

BDC Ballistics Calculator

Turn verified ammunition data into a trajectory, wind solution, printable range card, and the predicted distance for every mark in your reticle.

G1 + G7MOA + MILFFP + SFP

Prediction, not proof

Confirm the actual zero and every intended hold with live fire. Published velocity and BC can differ from your rifle and conditions. This solver deliberately excludes spin drift, Coriolis, aerodynamic jump, uphill/downhill fire, and transonic instability.

Computed solution

Trajectory versus line of sight

Bullet pathLine of sightWind drift

At maximum range—elevation correction

Remaining velocity——

Air density——

Bore elevation—relative to sight line

Custom BDC map

Map your reticle marks to distance.

Enter the angular value of each hold below center. The calculator finds where the predicted post-zero correction reaches that mark. Use values from the scope manual—visual spacing is not a measurement.

Range card

One solution, both angular systems.

Elevation is the upward correction required after the selected zero. Wind values are for the entered wind speed and angle; positive drift is downwind.

Range	Path	Elevation	Wind	Velocity	Energy	Time

What this replaces

The useful part of a discontinued product-specific tool.

This independent calculator is designed for shooters who lost access to Nikon Spot-On or another retired BDC utility. It accepts any manufacturer’s G1 or G7 coefficient and any reticle whose angular marks are documented. Nikon and Spot-On are trademarks of their respective owner; Optics Intel is not affiliated with or endorsed by Nikon.

Model boundary

A transparent point-mass prediction.

The solver numerically integrates a standard G1 or G7 retardation function with gravity, standard-atmosphere density adjusted for temperature, elevation, and humidity, plus a horizontal wind vector. It assumes level fire and a stable projectile represented by the entered BC.

Field workflow

Calculate, print, verify, correct.

Chronograph the ammunition through the actual rifle.
Measure bore-to-optic center height.
Use the bullet maker’s BC and matching G model.
Confirm the primary zero.
Shoot every intended BDC distance and write the verified distance beside the prediction.

Published-data cross-check

The solver is tested against a manufacturer table.

Federal publishes velocity and 10 mph wind-drift data for its 140-grain 6.5 Creedmoor Sierra MatchKing load: 2,675 fps muzzle velocity and a .261 G7 BC. With those same inputs, this solver stays within 20 fps and 0.5 inch of Federal’s table through 500 yards. The automated build test locks in those tolerances.

Open Federal’s published ballistics table →

Range	Federal velocity	This solver	Federal drift	This solver
100 yd	2,509 fps	2,506 fps	0.6 in	0.7 in
200 yd	2,350 fps	2,343 fps	2.7 in	2.7 in
300 yd	2,196 fps	2,186 fps	6.5 in	6.3 in
400 yd	2,048 fps	2,035 fps	11.9 in	11.6 in
500 yd	1,905 fps	1,889 fps	19.2 in	18.8 in

Technical references

Inputs and assumptions

NOAA/NWS: ICAO standard atmosphere — standard sea-level pressure, temperature, and density used for atmospheric normalization.
NOAA/NWS: pressure definitions — why station pressure and sea-level-adjusted pressure are not interchangeable.
Federal Premium rifle ballistics table — the published velocity and wind-drift dataset enforced by the automated solver cross-check.
Hornady Ballistic Calculators — manufacturer solver for independent trajectory comparison.
Optics Intel: How to Zero an LPVO — live-fire zero and confirmation procedure.