I believe you misunderstood, winnie.
The fuses were save until a certain time after firing the round,
So if there was something in the way in the first few yards of flight the round wouldn't explode.
The MG FF used the "Bodenzünder (Bd.Z.) 1511, 1512 and 1513.
Funktion: Centrifugal arming using steel balls that move outward. When air resistance slows down projectile spin, balls move back toward center
and cause a spring to force firing pin into detonator for self-destruct