Where the bullet actually is.

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.

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.

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.