We did that in Vietnam. Discover a VC ammo cache, replace a percentage of the ammo with ammo containing HE instead of powder, let the VC go back to their cache & blow themselves (and their rifles) up.
I’ve heard that it was done on Operation Fishhook, and other incursions into Cambodia and Laos. It brings to mind some of the sabotaged weapons that GIs found in Iraq. Nasty business, war....