Even firearms target backstops are called butts. I "worked the butts" at high-power rifle matches.
Go ahead, giggle if you must.
Some rock formations are also called butts.
(First time I worked the butts, I wondered how come everybody was wearing hearing protection. When the first round came over, I understood why.
CRACK!.... boom.)
How far behind the targets was that drainpipe and the arrow? Seems unlikely to have retained enough energy to penetrate that pipe that way with a target pile. Just interested in the probabilities involved.
Terry, 230RN