involved chopping down 12 inch to 24 inch diameter teak trees outside our perimeter in Vietnam (1966).
About a dozen of us, manning a counter mortar flash base, became bored during the daytime (enemy confined their activities to hours of darkness, mostly). So, we took turns, during the day, with our M2, chopping down teak trees. It was a competition to see who could chop down the biggest tree with the fewest rounds. Usually took only 5 or 6 rounds (ball ammo) to get the job done.
Each shot would result in pieces of tree trunk about the size of a 6 to 8 foot long 2x4 splitting off and sailing 10 to 20 feet into the surrounding jungle! The final, felling shot would usually be at a 6 or 8 inch diameter fragment of the tree trunk stubbornly holding up the tree canopy. At 200 yards, or so, it was a challenge to hit that small a target, but Ma Deuce was up to it! It was a sight to see a teak tree (as tough as our American Bois de'Arc, but much taller, thicker tree) collapse to the ground.
We stayed in that location for 30 days, just 11 of us, 5 clicks from the nearest supporting position, and never were attacked by Viet Cong. Guess they respected a weapon that could chop down huge trees with 5 or 6 shots.
Oh, and we had M-16's, too.