Currently we use grapearls; they're essentially machines designed for combat, based on data we retrieved during our fight with Lordgenome seven years ago.

[Mmmm, this requires a bit more explanation than that.]

Lordgenome's forces wielded gunmen to subdue humanity - they were likewise machines he had created for combat, capable of operating with a skilled pilot. We rose up, stole their gunmen, and fought back. We stand united now, with little threat of war, but we have created the grapearls for protection in case we need it.

[...Though surprisingly, the knockoff gunmen aren't actually as effective as the originals!! Wow, who saw that one coming!!!]