It seems to me the recoil from something like a mounted shotgun would upset the drone.
Maybe they should bring back the recoilless GyroJet firearms. from fifty five years ago for such applications.
Tiger Tanaka’s rocket guns.
Maybe a low-recoil .410 round, with the expectation that firing would still cause short-term disabling of the drone, but that the should would also disable the target.
“...a mounted shotgun would upset the drone.”
A snowflake drone?