The Germans used cumulative circular charges (Hohlringladung) weighing 1.5 kg and 3.2 kg (TNT) during World War II to destroy weapon barrels. These round charges had a domed outer shape and a conical interior that created a cumulative effect on detonation, crushing or deforming the surrounding metal.
The 1.5 kg charge was used for machine guns (MGs) and smaller calibre (37 mm) guns, while the 3.2 kg charge was intended for larger calibre artillery pieces and field howitzers. These circular charges were likely used in the earlier stages of the war. Later on, internal barrel-mounted Z-type demolition charges were introduced for this purpose.
(Source: Ger.Dem.Eq, 1944)
