Blount was appointed Lieutenant of Hammes in the Pale of Calais on 6 April 1470. Blount's father died 1 August 1474, and was buried at the Greyfriars, London. His eldest son and heir, William Blount, had died of wounds received at the Battle of Barnet on 14 April 1471, and William's underage son, Edward, succeeded as 2nd Baron Mountjoy. When Edward died without male issue on 1 December 1476, John Blount inherited the barony as next male heir.