I found an ord file that used a Bullet class label. It is the combat_speeder missile ord.
[OrdnanceClass]
ClassLabel = "bullet"
[Properties]
ImpactEffectWater = "watersplash_md"
GeometryName = "com_weap_missile"
ExplosionName = "all_weap_hover_combatspeeder_missile_exp"
TrailEffect = "smoketrail"
LifeSpan = "7.0"
Velocity = "40.0"
Gravity = "1.0"
Rebound = "0.0"
Damage = "400"
VehicleScale = "0.4"
PersonScale = "1.0"
DroidScale = "1.0"
BuildingScale = "1.0"
AnimalScale = "1.0"
//TurnRate = "2.0"
//WaverRate = "4.0"
//WaverTurn = "1.0"
OrdnanceSound = "com_weap_inf_ord_hum_rocket"
CollisionSound = "com_weap_rocket_small_exp"
//LockedOnSound = "com_weap_launcher_missile_guided
Copy and paste this into a normal weapon ord and you should be able to give it geometry and stuff like a bullet.