Abstract: A firearm handguard attachment device comprises a barrel nut having a forward end, a rearward end, and a circumferential recess between the forward end and the rearward end, the recess having an uninterrupted surface and defining a forward shoulder and a rearward shoulder, a handguard having a forward end and a rearward end and configured to be slid onto the barrel nut, the handguard having a transversely extending opening in a lower portion thereof, the opening having a seat at each opposite end, a pair of wedges, one wedge of the pair being installed in one of the seats and the other wedge of the pair being installed in the other seat, and at least one fastener for drawing the wedges toward one another. The wedges are configured to engage the uninterrupted surface of the recess to prevent axial translation of the handguard relative to the barrel nut and to prevent axial rotation of the handguard relative to the barrel nut.