How to acquire the reference to a Niagara system in a Blueprint via C++?

[jwatte]

Shouldn’t the name be "BeamParticles" ?
Anyway, you should see the component in the scene hierarchy for the actor, assuming you attach it correctly.
Once you see it, you should be able to configure it just like you’d configure a StaticMesh or whatever.
If that is all the code you wrote then you haven’t yet attached it correctly.

You probably want some other component in between, too, if you’re going to be building a complex weapon out of it.

	UPROPERTY(EditAnywhere)
		USceneComponent* SceneRoot;
	UPROPERTY(EditAnywhere)
		UNiagaraComponent* BeamParticles;

// Sets default values
AMyActor::AMyActor()
{
 	// Set this actor to call Tick() every frame.  You can turn this off to improve performance if you don't need it.
	PrimaryActorTick.bCanEverTick = true;
	SceneRoot = CreateDefaultSubobject<USceneComponent>("SceneRoot");
	SceneRoot->SetupAttachment(this->GetRootComponent());
	BeamParticles = CreateDefaultSubobject<UNiagaraComponent>("BeamParticles");
	BeamParticles->SetupAttachment(SceneRoot);
}