Issue with beam rotation

I’m trying to make a particle system for a weapon which shoots a flat wide beam, but having some difficulty. I was able to make something close to what I wanted using a beam emitter with a large X size. But, the problem is that I can’t figure out how to force it to always be flat and not rotate towards the camera.

The particle system is spawned attached to the weapons muzzle, and the target is set as the result of a singe line trace. Everything seems right except that it rotates slightly to face the camera. Is there any way to prevent that? I’ve tried everything from using Orientation Lock Axis, to every type of Screen Alignment available and can’t figure out how to get the desired result.

Any idea why this won’t rotate properly?

Here’s what I have set up right now:


Thanks so much!

P.S. I also asked this in AnswerHUB a week ago but haven’t heard anything yet so figured I’d try the forums as well. Hope that isn’t an issue.