Postal scale, and I swear it weighs in at 5lbs 14ozs. I couldn't believe it either. My P-Lyte Deluxe weighs just a hair under 7lbs on the same scale. In any case, I will weigh it on another scale when I get a chance, just to double-check it.
Jump on your bathroom scale with the bass. Record the weight
Jump on the same scale without the bass.
Subtract the second number from the first. Pretty much a foolproof way to weigh your bass.