M500 fuze
Contents
M500 – mechanical time fuze with impact action
Fuze M500 - a mechanical time fuze with dual-purpose impact and remote (time) action. Used for 105 mm and 155 mm howitzer artillery projectiles and for mortars of 105 mm caliber and above
Fuzes of this type are set by turning the movable part of the body (the scale) until the required time mark coincides with the fixed part of the fuze body (the index).
Technical specifications
- length (with detonator): - 12.7 cm;
- weight (with detonator): - 907 g;
- time setting: - from 2 to 75 s;
- lowest rotation rate for arming: - 2,000 rpm.
Usage notes
Warnings:
Heavy rain may cause premature functioning of the fuze during firing.
When firing air bursts from 155 mm guns, misfires may occur on charge 1 or 2 because of insufficient setback force to release the timing mechanism. In that case, however, the fuze will function on impact.
From experience. When the timing mechanism was set to the level of the first mark (impact action), duds of the projectile were observed. Set the mechanism to the end of the scale (70–75 s) and it will function 100%
The M500 fuze is not safe. Dropping or rough handling of a projectile fitted with an M500 fuze may cause the detonator to function and individual parts to fall out of it.
The safety pin must be removed immediately before firing.
Fuze Setting
Setting the fuze:
The fuze is screwed into the fuze socket of the projectile and tightened with a wrench. The safety pin must be removed before firing. If the round is fired with the safety pin in place, the fuze will not be initiated.
Setting for remote (time) action:
It is set by turning the time-setting scale (in the direction indicated by the arrow on the fuze body), graduated from 2 to 75 seconds, until the required numerical index coincides with the mark on the body.
Setting for impact action:
It is set by turning the time-setting scale (in the direction indicated by the arrow on the fuze body) from the S position (service position, safe handling) to the first ungraduated mark.
The fuze will also function on impact (the fuze will be initiated) if its time to meeting an obstacle is less than the time set on the setting scale.
From experience. When the timing mechanism was set to the level of the first mark (impact action), duds of the projectile were observed. Set the mechanism to the end of the scale (70–75 s) and it will function 100%
Oleh Syrota (Georgich©) for the Armed Forces of Ukraine / Entropia.com.ua
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