It’s not the laser rifle - it happens with other weapons as well, including the basic AR.
I think it’s the new penetration system that came in Derleth:
It just doesn’t work exactly (or only) as intended, as projectiles with 0 remaining damage continue traveling on, shredding armor on their path.
This is particularly noticeable with Chirons, as they have many overlapping body parts. A burst with AR will regularly shred 15+ armor.
Or that’s what I believe based on my experience. If anyone has a better explanation it would be great.