ammunition in 1951 with the .280/30 being re-designated as the "7 mm MK1Z". Selection of 7.62 NATO Britain, Canada and the United States, founding members of NATO, had all signed an agreement that member states would develop and deploy common small arms and cartridges, developed through competitive trials in co-operation together. Britain and Canada had been open about their developments, and the Americans claimed they were not developing a round of their own and were known to be trialing the British designs. In fact, Colonel Rene Studler, head of the US Small Arms Bureau of Ordnance had been diametrically opposed to a bullpup design and the .280 cartridge, and had started two secret projects on a .30 calibre cartridge. These were the T25 rifle at Springfield Armory under the direction of Earle Harvey, firing the T65 cartridge being developed at Frankford Arsenal. Between 1947 and 1952 the British and Canadians made clear to the United States they were aware of their secret work, stating that it was against the open, collaborative nature of the agreement, making their disapproval clear. Matters took a turn for the worse when Rene Studler went on record, stating that, any non-American design was "a waste of time" and refused point blank to accept any "foreign" design. It was learned that Studler had gone so far as to bury reports that suggested the .280 was superior in US testing. During firing tests in 1950 at the Aberdeen Proving Ground the Maximum Average Pressure (MAP) for .280 British ball ammunition was measured at . The highest measured maximum pressure was . A change of government meant that the 7 mm, EM-2 and Taden gun projects were abandoned soon afterwards by Winston Churchill, who returned as the prime minister and desired commonality between the NATO countries. Small amounts of .280 British ammunition were later produced during the 1960s for various small arms trials. At the same time, the British and Canadians, who were very impressed with the cartridge originally planned to have their FN FAL rifles chambered in .280. However, eventually, they agreed to a quid pro quo where the British would use the US-derived .30 (by now the 7.62) while the Americans accepted the FN FAL. This too proved not to be the case, and the US eventually chose their M14 rifle over the FAL. After .280 The .280 British concept would later prove to have been