Apart from the impossibility of aiming at it, the mathematical “point” would be of no use as a bull’s-eye. If the bullet hits it, or hits a pin’s point (which is the smallest practical substitute for the mathematical point), the point disappears and there is no means of telling if the centre of the bullet struck that point or not.
M. Gastinne-Renette’s solution of this problem is extremely simple. It is to make the bull’s-eye of exactly the diameter of the bullet fired at it.
If a bullet hits a bull’s-eye which is exactly of the same diameter as itself, and no part of the bull’s-eye remains visible at an edge of the bullet hole, then that bullet has hit absolutely central in the bull’s-eye.
The next difficulty was that such a small bull’s-eye is difficult to aim at with a pistol.
This was overcome by enclosing this absolute bull’s-eye called the carton, in a larger bull’s-eye, called the aiming bull’s-eye.
The carton is left white and the aiming bull’s-eye printed black.
PLATE 8. THE GASTINNE-RENETTE 16 METRES TARGET
This target has a 13⁄16 black. The ring is to facilitate judging
This aiming bull’s-eye is of the diameter of three bullet widths.