A Southwest Washington man described by police as the leader of a multimillion-dollar "Dial-a-Dope" narcotics distribution ring whose customers placed orders for cocaine and heroin by telephone pleaded guilty yesterday in U.S. District Court here to a drug conspiracy charge.

James R. Shaw, 29, of 101 Sixth St. SW, who was indicted on numerous drug possession and distribution charges in the scheme, also pleaded guilty to one count of unlawful use of a telephone.

Roger Cobble, 28, of 3853 Ninth St. SE, who prosecutors said worked for Shaw, accepted telephone orders and made drug deliveries, pleaded guilty to a single count of unlawful use of a telephone.

Shaw and Cobble are among 13 persons indicted in July in connection with the drug distribution ring, which worked out of apartments in Southwest Washington. Two other men, Maurice S. Young, 26, and his brother, Herbert Young, 32, both of 2518 Q St. SE, pleaded guilty earlier to drug possession charges.

U.S. District Judge Thomas J. Hogan set Shaw's sentencing for April 8 and Cobble's for April 9. Shaw faces up to eight years in prison and a fine of $60,000, and Cobble faces up to four years in prison and a $30,000 fine.