Washington: A 30-year-old Secret Service audiotape, showing the chaotic aftermath of Ronald Reagan's shooting, has finally released.

The Secret Service released the tape on Saturday in response to a public-records request from Del Wilber, a Washington Post reporter whose book, "Rawhide Down: The Near Assassination of Ronald Reagan," will release next week.

Just over 10 minutes, the tape captures the urgent, confused yet coolly methodical radio communications among agents on the scene and the Secret Service command post, starting when the President and his entourage walked out of the Washington Hilton while John Hinckley Jr, with a pistol, stood waiting.

Hinckley opened fire, wounding press secretary James Brady in the head, police officer Thomas Delahanty in the back and Secret Service agent Timothy McCarthy in the abdomen before his last bullet ricocheted off the limousine, grazing Reagan's rib and lodging in his lung.

Less than four minutes after Reagan left the Hilton, the car carrying the stricken President arrived at the hospital.

Reagan had suffered extensive internal bleeding, but his gunshot wound was not discovered until doctors examined him.

As it turned out, he did not enter on a stretcher but got out of the car, walked in with the help of agents and began to collapse before those around him picked him up and carried him to the emergency room.

Doctors were able to stabilise his blood pressure in short order before removing the bullet in surgery.

(Agencies)