Standing 16.2 hh (168 cm), Boomerang was ridden in show jumping most successfully by Eddie Macken, as well as by Liz Edgar (Broome), Johan Heins and Paul Schockemöhle.
Murphy hunted him with the Kilmoganny Harriers, jumped him in novice classes on the Tipperary/Kilkenny/Waterford gymkhana circuit and later sent him to "finishing school" with 1969 European showjumping champion Iris Kellett in Dublin.
A rich German owner, Dr Herbert Schnapka, eased Macken's way by providing horses for him to ride in the Schockemöhle yard.
Boomerang did not knock a single fence in the first three rounds and helped Con Power on Rockbarton, Gerry Mullins on Ballinderry and John Roche on Maigh Cullin to a bronze medal behind Britain and Germany.
[2] Boomerang was in the individual lead and heading for gold when a judge made a late decision that he had hit the tape at the water jump, and he and Macken finished in fourth place.
That autumn Boomerang and Macken won the main class at Calgary every day and took the du Maurier Classic Grand Prix in September.
With a double clear, they were fourth in the Grand Prix at Olympia just before Christmas, and that was to be Boomerang's last major individual outing with Macken.
Con Power on (Coolronan 1977, Castlepark 1978 and Rockbarton 1979), won the Aga Khan Trophy at the RDS Dublin (Ireland's Nations Cup) from 1977 to 1979.