Are all projectiles affected by gravity in BF3?

According to this page, the bullet-drop on gun-projectiles varies from gun-to-gun

Bullet drop is -15 m/s for all the weapons except for AS VAL and all sniper rifles (excluding SKS) its -9.81 m/s
Shotgun shells have their own drops which are mentioned at the chart.

I can't find any information about bullet-drop for vehicle projectiles, but it's not unreasonable to believe they also have separate drop-rates. I'll update this answer if I find more info.

Anecdotally, I can state with near certainty that the helicopter and AA projectile-drop-rates are much less than the other guns, possibly non-existent.