He practiced law in New York City as a member of the firm of Oudin, Kilbreth & Schackno, with offices at 34 Pine Street.
Schackno was a member of the New York State Senate (21st D.) from 1919 to 1933, sitting in the 142nd, 143rd, 144th, 145th, 146th, 147th, 148th, 149th, 150th, 151st, 152nd, 153rd, 154th, 155th and 156th New York State Legislatures; and was Chairman of the Committee on Codes in 1923, and Chairman of the Committee on the Judiciary in 1924.
During the session of 1933, Schackno introduced a bill to add two judges to the courts in the Bronx, and on November 7 he was elected to fill one of the additional seats on the bench.
He was a delegate to the New York State Constitutional Convention of 1938.
He was re-elected to the City Court in 1943, and remained on the bench until the end of 1948 when he reached the constitutional age limit.