At least the GK version is not a barrage weapon regardless of barrage being part of the fluff description it does not have the rule in the weapon profile. It does always scatter the full 2D6 without any BS subtracted or any help from servoskulls.
I couldn't really find it answered out there, so that's why I asked. There was one place that said it wasn't, but I couldn't find any rule besides the psyker one not being able to use a firepoint.
Wife: "How much do you have invested in these ... miniatures?"
Me: "I don't think invested is the right word."