List of weapons with reduced specials
From Ephinea PSO Wiki
It is a common misconception that weapons with rarity 9 stars or less is reduced, and those with 10 stars are unreduced with some exceptions. The actual rule is every weapon with hex value preceding Photon Claw can be reduced, if it comes with a special with reduced form (i.e. not sacrificial) and it attacks more than one time or capable of acquiring more than one target per attack. Specials of all other weapons are unreduced.
Swords
Daggers
Partisans
Slicers
Mechguns
Shots