Arma 3 Version: 1.98.146373 (Reverified on 2.04.147975)
When shooting (and hitting) man entities near rocks of the classes: "Land_SharpRock_wallV" & "Land_SharpRock_wallH" a significant frame drop will occur.
This seems to be tied to the hit animation in some way, as if units have allowDamage set to false no stuttering will occur, additionally, having a mod such as No Hit Animation installed reduces the likelihood of frame drops.
The distance between the rock and man must be within approximately 50 meters.