Coniston Water per hour () in "Blue Bird K4". Between 1956 and 1959 Sir Malcolm's son Donald Campbell set four successive records on the lake in "Bluebird K7", a hydroplane. In 1966 Donald Campbell decided that he needed to exceed 300 miles per hour (483 km/h) in order to retain the record. On 4 January 1967, he achieved a top speed of over 320 miles per hour () in "Bluebird K7" on the return leg of a record-breaking attempt. He then lost control of "Bluebird", which somersaulted and crashed, sinking rapidly. Campbell was killed instantly on impact when decapitated by the K7's
.300 H&H Magnum at Camp Perry in 1935, and it was used again to win the international 1,000 yard competition in 1937. Winchester chambered the Model 70 in .300 Holland & Holland Magnum in 1937. The cartridge offered superior ballistics to the .30-06 for long range, and the .300 H&H is almost as versatile with all bullet weights and types, especially if well-developed handloads are used. It excels with the heaviest .30-calibre bullets in the 180–220-grain range. SAAMI has set the pressure limit for this cartridge at 54,000 P.S.I. Its case length calls for a full-length magnum action, and surplus military actions chambered