Very interesting video. Would you be able to add some ballistic information in future videos? The weight of the grenade, the weight of the explosive fill, the meters per second, etc....? Thank you in advance for your consideration.
If I remember correctly, Britain used air compression fuze occasionally. which is pretty much an isolated air inside a shaped sheet metal. The thickness and the hardness of the outer shell is adjusted for a proper delay. Japan used the same principle in their WW2 Ho-103 machinegun with the Ma-102 rounds, their army 20mm had a similar counterparts called Gou hatsusei-shinkan (in which, translates to roughly "On-hard fuze"), and instantaneous explosion variant. I have to double check some stuffs on the sources but French used the Brit-type 20mm air column. Some of the Number 25x fuzes. Their usage continued to the post war era. They even made it into 30mm cannons for aerial uses.
