Luotirata

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Calculator

Point-mass RK4 integration on the standard G1/G7 drag tables, ICAO atmosphere with your own temperature, altitude and humidity. Everything runs in your browser — it works with the phone in flight mode at the range.

Atmosphere & angle

Air 1.2211 kg/m³ · sound 340.8 m/s · muzzle Mach 2.49 · SD 0.222 · form factor i(G7) 1.087

Drop & trajectory

-1500-1000-500002004006008001000Mach 1
Path relative to line of sight (cm)Range (m)
Range (m)Path (cm)Come-up (mrad)Velocity (m/s)
50-0.6 0.13 812
1000.0 0.00 775
150-3.4 0.23 739
200-11.4 0.57 704
250-24.3 0.97 670
300-42.6 1.42 637
350-67.1 1.92 605
400-98.2 2.45 573
450-136.8 3.04 543
500-183.7 3.67 513
550-240.0 4.36 484
600-306.8 5.11 455
650-385.4 5.93 428
700-477.4 6.82 401
750-584.8 7.80 375
800-709.5 8.87 351
850-854.2 10.05 331
900-1021.2 11.35 319
950-1212.4 12.76 310
1000-1429.0 14.29 303

Highest point 0.2 cm above the line of sight at 84 m. Point-blank window (±7.5 cm): 0–176 m.

This bullet goes transonic at 685 m

The shaded band on the chart is the transonic zone, Mach 1.2 down to Mach 0.8. Your bullet enters it at 685 m and crosses Mach 1 at 823 m.

In that band the shock wave sitting on the bullet's nose detaches and moves rearwards. The centre of pressure shifts, drag rises steeply, and the yaw-damping that keeps a spinning bullet pointed forwards weakens. Groups open up — not because the calculation is wrong, but because the bullet itself stops behaving predictably. Treat drop numbers past this range as an estimate, and expect more vertical dispersion than the trajectory suggests.

MOA vs mrad — and why 1 MOA is not 3 cm

1 mrad = 0.001 radian exactly, so it subtends exactly 10 cm at 100 m, 20 cm at 200 m, and so on. That is why metric shooters like it: the arithmetic is decimal.

1 MOA = 1/60 degree = π/10800 radian, which is 2.908 cm at 100 m and 1.047 inch at 100 yd — not 3 cm and not 1 inch. The "1 inch at 100 yards" shortcut is 4.7 % off, which is 2.4 inches of error at 500 yards. This calculator uses the exact definitions throughout and rounds only once, in click space, at the end.

One click on your turret is 0.1 mrad (1 cm @ 100 m). Because a turret can only move in whole clicks, there is always a leftover — shown above as a residual in cm at the target.

G1 or G7 — which drag model fits this bullet?

A ballistic coefficient is not a property of the bullet alone; it is a comparison against a reference projectile. G1 is a short, flat-based 19th-century shape. G7 is a long boat-tail. A modern match bullet resembles G7 far more than G1.

The practical consequence: a G1 BC quoted for a boat-tail bullet is not constant with speed — catalogues often publish banded values (one BC above 800 m/s, another below). A G7 BC for the same bullet stays nearly constant, so a single number carries the whole trajectory. If a G7 figure exists for your bullet, use it. G7 BCs are numerically about half the G1 value for the same bullet — that is expected, not a typo.

No small arm is hypersonic

Hypersonic conventionally begins at Mach 5 — about 1700 m/s at sea level. This load leaves the muzzle at Mach 2.49. The fastest commercial rifle cartridges (.220 Swift, .22-250) top out near Mach 3.5, and tank APFSDS rounds reach roughly Mach 5 — small arms do not. Anything you read about "hypersonic bullets" from a rifle is marketing.