Charge Beam Cannon

I recently got it after rolling at garapon. It seemed pretty good, but not as good as I had expected. How should I tune it (2 slots) and any tips on using it?

tune more speed and learn to lock down/aim you enemy.
hi shooter + great rapid beta. about ammo you can get it from ghost tree and other.
change beam canon if you tune more speed will be easily hit any target you want.

grapid + gforce
one grapid is enough speed to hit pretty much anything and with a gforce you can hit like 80+ damage on good hits.