I came very close to posting a bug report just now and finally figured out it was working as intended. I had a gun that was showing a different range depending on if I looked at the stats at Delta’s or in the Inventory. Only right before posting it did I realize it was likely because Bormin was holding it and had the increased range mutation.
I feel like the weapons screen in the Inventory should note this in a blue (or other color) text, just like it does with modifications due to attachments.