So I know when a Locust with a wound counter is killed, the counter flips over and potentially leaves a weapon behind. What if you kill it outright in one attack? Do you still grab a random wound token and flip it to see if he dropped a weapon? Seems odd that only a wounded Locust might drop a weapon. Sorry if this is in the rules somewhere, I can't seem to find it if it is.

Yep, this is in the rules. You still flip the next wound counter from the stack and if there is no dropped weapon you just discard it right away.

See: Dealing Wounds: Wounding Locust Figures (pg 19 of the rulebook)

"... it is killed. Remove the figure from the map and place a dropped weapon marker in its area. This is done by flipping its wound marker facedown, or if unwounded, drawing a new marker from the pile of unused wound markers. This marker is either discarded or becomes a dropped weapon marker as described on page 20."

Woo, thanks. I think I was suffering from reading the rules too much and skipped over it a few times.