I've been noticing some odd readouts on weapon damage numbers. For example, if I set in options to show base damage, without factoring player skills etc., a simple unmodded triple barrel shotgun shows 15 x 8 damage. When options are set to include player effects, the damage reading sometimes reads 12 x 8, and a moment later, say after equipping the weapon, it reverts to 15 x 8. There doesn't appear to be any skills / traits / perks / items etc. that account for the fluctuation. This is one example, but it happens to several of the base weapons I'm carrying.

Yeah, there's a bug with tooltips, so essentially you have to equip a weapon into your character's hands in order to know how your skills will affect its stats. However, the affects of perks are supposedly never reflected.

I believe I've worked out what's causing the anomalous damage numbers (in my case, at least); I have a light pistol that carries a mod that changes damage output to plasma, at the expense of slightly lower damage from the weapon. What's happening is, when I have this pistol equipped, the damage numbers for ALL of my inventory ranged weapons are mistakenly factoring in that damage penalty. As soon as I switch equipped weapon, the numbers show correctly.