US copper futures drifted quietly down at the open on Wednesday, as prices paused beneath recent highs and gathered momentum for another test of the psychological $3 a lb, traders said. Copper for December delivery down 1.45 cents at $2.9415 a lb by 10:30 am EDT (1430 GMT) on the New York Mercantile Exchange's COMEX division. Range from $2.9230 to $2.9735. COMEX estimated copper volume at 5,702 lots by 9 am.