When I enlisted in the Marine Corps in 1959 we were still armed for the most part with M-1 rifles, BAR's and Browning air cooled machine guns. The air cooled Browning was John M.'s answer to the German 08/15 "light" machine gun and doing away with the water jacket and heavy tripod lightened the Browning considerably. However, it remained a converted water cooled gun, and had no capability of rapid barrel change. In fact, changing barrels with a Browning was a time consuming, frustrating task, involving setting headspace by a trial and error method. In that respect at least the M-60 machine gun was a big improvement.

On the other hand, the Browning, especially the big .50 caliber, was an ideal aircraft machine gun, where keeping the barrel cool was not a problem and flawless functioning was at a premium. Once the problem of belts getting kinked by drastic aerial maneuvers had been solved, the Brownings performed without a hitch. One carrier task force reported carrying out an entire mission without a single failure with the Browning guns.

When Browning first demonstrated the original water cooled gun to a congressional delegation, by linking belts together he was able to fire the gun continuously for over a half hour, without a single stoppage or broken part. In the course of firing 20,000 rounds were expended, but dissatisfied with the results, Browning proceded to fire an additional 20,000 rounds without a stoppage or breakage. In response to suspicions that the test had somehow been rigged, Browning used a second gun to fire continuously for 48 minutes and 12 seconds, at a rate of 600 rounds per minute. Presumably the committee's collective ears were ringing at the conclusion of the tests.