1. - When your rounds are hitting something you see sprites versus the other guys hitting it.
2. - You will only be hitting something inside a small sight window from a wirble that you will know it when you see sprites and your tracers to help you lead if that is your method. The real effective range in the game is about 1200yds, past that, most players cannot judge the lead and elevation.
You can test all of this by creating a custom arena from the "Player" tab. Choose the arena called gunnery. Once it downloads, exit out of it and use it offline. From A1 spawn your wirbel NE up onto the mesa over the field. The drones will fly withing 800 of your position, and you can use the lead computing gunsight to help you see how to aim. And the gunsight reticle I built for the wirbel works with the LCG green cross.