the bolt 21 it is conveyed rearwards by the bolt against the action of the spring 24 the clockwork 25 has previously been brought to armed position whereby the mentioned stopping element in the clockwork has been removed so that the pin 26 due to the mentioned acceleration stress protrudes further into the clockwork thereby to cause the balls 27 to be forced into radial grooves 37 in the fuze as soon as the acceleration stress on the subprojectile ceases the bolt 21 will partly due to deceleration caused by the air resistance partly due to the effect of the spring 24 move foreward through suitable dimensioning of the spring 24 the initiation time thus can be varied since the balls 27 no longer limit the movement of the bolt 21 the bolt can move all the way to the firing pin 34 which initiates the primer 29 and then in turn the primary detonator 30 the secondary detonator 32 the bursting charges 35 and 36 and the main bursting charge 5 are initiated in the shown embodiment the firing pin 34 is firmly connected to the subprojectile 2 it may however also be flexibly arranged in the housing 34a see fig2 in such a way that it in safe position does not protrude outside the housing 34a and thus cannot be reached by the primer 29 in the bolt 21 in armed position the firing pin 34 on the other hand is brought forward to the position shown in.