Booster, M20, M20A1, M20A2
The combination of this booster and the Fuzes M48, M48A1, or M54 is boresafe, since the rotor of the booster restrains its detonator out of line with the flash hole connecting the detonator of the fuzes with the closing cup charge of the booster, and positively interrupts the channel until the projectile has cleared the muzzle of the weapon. This booster is used in conjunction with standard contour fuzes in the Shell, HE, M48, for 75mm guns.
The M20 Booster has been modified by enlarging of the flash hole in the rotor cover. The modified design is known as the Booster M20A1.
Superseded by M21 Booster.