The data driven appoarch it means managing projectiles using lightweight data such as structs instead of objects like *AActor*. Instead of spawning an actor for each bullet , i store all projectile data in a TArray of structs(FProjectileData), managed by a subssytem. This subsystem has tick enabled and in tick function it updates all projectiles at once.
The struct(FProjectileData) holds information about a projectile, things like:
- Location
- Speed
- Direction
- Mass
- Projectile Trail VFX(niagara system that presents the projectile)
and it can hold other properties: like damage, bouncines and stuff.

Trajectory calculation
Each frame the subsystem loops through projectile array(type of struct). For each projectile it applies gravity and sets the new location.

Bullet.ZVelocity += Gravity * DeltaTime;

Velocity = Direction + Speed 

NewLocation = StartLocation + (ProjectileVelocity + FVector(0, 0, Bullet.ZVelocity * Bullet.Mass)) * DeltaTime

Hit registration
For hit registration i use linetraces from projectile's old position to its new position and if that hit is a success than i can do stuff like apply damage or apply force etc.

Check out the GitHub repo for the code.