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 for the .308 Norma Magnum or the .300 Winchester Magnum offered a lower cost alternative for similar ballistics in the 1960s. The long .300 H&H case was designed for loading cordite, and those two modern magnum cartridges offered similar powder volume in a shorter case better adapted to ballistic uniformity with United States Improved Military Rifle (IMR) smokeless powder. It has never been as popular as the .30-06; but the mystique of well-crafted rifles chambered for the .300 H&H keeps the cartridge in use despite its repeatedly reported demise. The .300 H&H is a fine African plains game cartridge, and