When I was about 9 a bunch of cherry bombs came into my possession and a buddy of mine came over who like to play WW2 as much as me. Lo, there was a pea gravel pile about 50 yards from our barn where all the krauts were holed up and they needed flushing out. Any survivors could be picked off with our BB guns you see. So, we found a 2 in galvanized pipe about 3 ft long and buried one end in the gravel and slanted/aimed it by country reckoning. One would dump a lit cherry bomb down and the other would quickly pour a double handful of pea gravel down the muzzle. Worked fantastic but we had to quit when our barrel developed a lengthwise split. The angels were kept busy guarding two West Texas kids for sure.