Base Ignition Fuze Mk 10 Mods 3, 4, and 5 (Obsolete)

Projectiles used in

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Material

Description: This fuze consists of a single body unit containing a striker carrier, an anti-creep spring, and a primer-magazine head. An integral tracer is located in the after end of the fuze body. In the unarmed position, as illustrated, the firing pin is held offset from the primer by a pair of centrifugal lock bolts. The firing pin is pivoted in the movable striker carrier, which is held away from the primer by an anti-creep spring.

Operation: When the projectile is fired, the gases from the propelling charge force a small firing pin into the tracer primer, igniting the tracer-starter mixture, which in turn ini-tiates the tracer pyrotechnics. Centrifugal force causes the two lock bolts to move out-ward against their spring, unlocking the pivoted firing-pin. The firing pin then rotates into the armed position, where it is aligned with the fuze primer. On impact, the striker carrier moves forward against the anti-creep spring, bringing the firing pin against the primer and initiating the black powder in the fuze magazine.

Remarks: Because of the peculiar shape of the firing pin, the effect of acceleration in the gun causes it to lag. This force is greater than centrifuagl force; so during the acce-leration stage the striker cannot align itself with the primer. When acceleration ceases, centrifugal force takes charge and rotates the firing pin into alignment.

Figure 105. Base Ignition Fuze Mk 10