I don't know where to post this or if this has been mentioned/being fixed in the next patch.
Use any gun switch to any melee the ammo count for that gun remains the type of ammo that gun uses will count towards challenges. Using the powerfist after using the assault rifle was counting 5.56 gun kills on super mutants.
The forum has been set to read-only mode. For community discussion and questions, head over to our Discord: https://discord.taleoftwowastelands.com