A sabot is a bullet that is smaller than the bore diameter and is incased in plastic. This protects the bullet from the blast and gets a higher velocity. Not sure if they are legal in Wash or not.

A jacketed bullet has a outside skin on the bullet that is not lead. For instance, the powerbelts with copper have a thin copper outside skin.

here is a sabot:

http://www.basspro.com/webapp/wcs/st...003000_400-3-3

a jacketed bullet:

http://www.basspro.com/webapp/wcs/st...003000_400-3-3

and an all lead bullet (with lube)

http://www.basspro.com/webapp/wcs/st...003000_400-3-3

one confusing thing is that bullets like powerbelts have a plastic "skirt" that is BEHIND the bullet. This does not make it a sabot. That is only if the plastic extends around the bullet