btw engineers you don't have to build a little stick and measure w ur little ruler how far away it is. u can just slap ur charge right on the surface
from the old guide:
In addition to safety, the trainee should be aware of the capabilities of the standard five hundred gram charges they are issued. An average detonation of one charge can produce an explosive force reaching seven thousand two hundred meters per second, and while the explosion does not innately produce shrapnel it does throw superheated earth or sand, metal or wood shards, or anything else it displaces at these speeds
...
A shaped plastic explosive charge could penetrate the average blast door at around five inches thick, and create a hole large enough for a man to duck through.