BD, M38 Practice
The M38 Practice Fuze is similar to the M38A1. However, no booster is used so that the closing cap consists only of a threaded cup with a hole in the center which is closed with a paper disc. The detonator assembly becomes an igniter assembly containing priming mixture and black powder.
The function of the two fuzes are the same until the force of impact when, in the practice M38, the firing pin strikes the priming mixture which ignites the black powder igniting charge.