How is bullet drop estimated without a chronograph chart?

The calculator uses a simplified point-mass drag model: it derives a retardation coefficient from the G1 ballistic coefficient, steps the bullet downrange in small time increments, and accumulates gravity drop. It is an approximation, not a substitute for verified dope, but it is close enough to pick the right hash.

What is reticle subtension?

Subtension is the angular value a reticle feature covers. A BDC hash that sits 3 MOA below centre subtends 3 MOA, which equals about 3 inches at 100 yards or 18 inches at 600 yards. Matching drop in MOA to the hash subtension tells you which mark to hold.

Why convert drop to MOA or MRAD?

Scope reticles are angular, so a drop of 24 inches at 400 yards must be converted to angle before you can match it to a hash. One MOA equals 1.047 inches at 100 yards; the tool scales that with distance and divides drop by it to get the angular holdover.

Is this safe to use for ethical hunting shots?

Treat the output as a starting point only. Atmospheric conditions, your exact load, and barrel differences all shift real impact. Always confirm holdovers on a range at known distances before taking a field shot, and keep shots within your verified envelope.

Does this account for wind or angle?

No. This tool solves vertical drop and BDC matching only. Wind drift, uphill or downhill angle, and spin drift are separate corrections you must add from a full ballistic solver or field experience.

What is the Hunting BDC Reticle Holdover Calculator?

Enter your cartridge ballistics — muzzle velocity, ballistic coefficient, zero range — and a hash subtension to match the correct BDC holdover point to shooting distance. For hunters using BDC scope reticles in the field. Runs in your browser. It runs free in your browser on Gera Tools, with nothing uploaded.

Hunting BDC Reticle Holdover Calculator

Name: Hunting BDC Reticle Holdover Calculator
Creator: Gera Tools
License: https://creativecommons.org/licenses/by/4.0/

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A BDC reticle is only useful if you know which hash to hold on at a given range. Most hunters zero at 100 yards and then guess the holdover — or worse, learn it the hard way in the field. This calculator models your cartridge’s drop, converts it to the same angular units as your reticle, and maps each shooting distance to the nearest hash mark so you can verify your holds at the range before the season opens.

How it works

The tool runs a simplified point-mass trajectory and then matches drop to your reticle. The angular conversions used are:

1 MOA  ≈ 1.047 in per 100 yd
1 MRAD ≈ 3.6   in per 100 yd
drop (angular) = drop_inches / (unit_per_100yd × distance_yd / 100)
hash to hold   = round( drop_angular / subtension_per_hash )

Drop itself is accumulated by stepping the bullet downrange in small time slices, applying a velocity-dependent drag retardation derived from the G1 ballistic coefficient, plus constant gravity. The crosshair zero is subtracted so distances inside the zero read as zero holdover.

Example and tips

A 2,900 fps load with a 0.45 G1 BC zeroed at 200 yards drops roughly 9 inches at 300 and 26 inches at 400 yards. At 400, that is about 6.2 MOA, so on a reticle with 2 MOA per hash you would hold on the third hash. Always verify these holds on a range at true measured distances before trusting them in the field — this model ignores wind, shot angle, and your barrel’s individual velocity.

MOA vs MRAD reticles

BDC reticles come in both MOA and MRAD (milliradian) subtension flavours, and mixing them up produces large errors. The key facts:

1 MOA ≈ 1.047 inches per 100 yards (commonly rounded to 1 inch at 100 yd)
1 MRAD ≈ 3.6 inches per 100 yards (or exactly 10 cm at 100 m)

A 3 MOA hash sits about 3 inches low at 100 yd and 12 inches low at 400 yd. The same angular value expressed in MRAD would cover far more physical distance, so check your scope manual carefully before entering the subtension per hash.

What the model includes and excludes

The simplified trajectory model accounts for: muzzle velocity, G1 ballistic coefficient drag, gravitational drop, and sight-height parallax. It does not account for wind drift (the dominant field error at hunting ranges), uphill or downhill angle, altitude and air-density effects on BC, or spin drift. Use the chart to choose the starting hash for each distance and then confirm those holds on a measured range with your actual load. Real recorded dope from your rifle will always be more reliable than any model.