If you can find one of these, I've been using one for the past year and I've been impressed. Not great for rifles indoors or if you're RO-ing a lot of Open pistol shooters.
http://www.honeywellsafety.com/Products/Hearing/Intelligent_Hearing_Protection/QUIETPRO_QP400.aspx?site=/usa
AVAILABLE FOR DOD, FEDERAL, STATE, AND LOCAL GOVERNMENT AGENCY ORDERING.