IF you are falconer musket2, investing into circling snipe until damage cap is nice, you will hit damage cap twice with the snipe bounce attribute in aoe.
And circling covering fire is decent aoe.
Headshot will not combo with circling at all. Headshot is aimed so it is better if you like single target and pvp. It will knock a player and make the player spin around, plus int and spr Debuff. Headshot attribute changes into 2 overheat so it will outdamage snipe vs singletarget. Vs aoe, it cannot beat circling snipe bounce though.