If you pick up any silver and/or gold sword, they are not meant to be used as a weapon, they have lousy stats for that.
These items are actually a tool for upgrading your other weapons:
Silver swords are just like the Exp Gunblades from PSO2, their only purpose is to be used as enhancement fodder.
Gold swords can be use like the silver ones for more weapon exp, or you can trade in 10 of them at the item exchange for an N-Augmentation Success Rate +10%
If you do attempt to use these sword as weapons, it only will make things more difficult for your self since they are not made for combat, I have seen several players trying to do this and struggle even on basic mobs or wonder why they can't get their Battle Power high enough to unlock story mode stuff and UQs.