If we're going to use Vietnam as a case study, anyone have any statistics as to the Australians armed with the L1 did, or would their differing infantry tactics make such a comparison an impossibility?
I joined the Australian Army in 1977. I served with numerous veterans of Vietnam, Malaya and even several of Korea. I trained in the same tactics that were utilised in Vietnam.
I'd suggest that the very different approaches of the two military forces make comparisons almost impossible. The Americans benefitted from an enormous logistic system which catered to their every whim and provided them with massive quantities of ammunition. Therefore they relied heavily on firepower to achieve the same objective that the Australians, because they were reliant on a relatively tenuous logistics system which stretched back to Australia, had to utilise men to do. Ammunition was precious and not to be wasted. Therefore fully automatic weapons were to be used sparingly. The US military would not hesitate to drop millions of dollars worth of HE on an objective and fire millions of rounds of ammunition in order to declare it "clear" of the enemy. The Australians would actually go and look to see if they were there and then engage them.
When the Australians, under US auspices in 1965-6 developed a 7.62mm Minigun equipped M113 (quite independent to the M163 AA system), it's tactical value was questioned openly by the Australian officers who witnessed its trials, simply because it directed too much fire in too small an area (roughly equivalent to six GPMGs), in their opinion. The result was that the vehicle's development was abandoned.
The L1a1 SLR was the right weapon for Australian theory and doctrine. Aimed, controlled and directed fire (by NCOs) was how they believed contacts should be prosecuted. Still is.
The M14 was the wrong weapon for the theory, doctrine and practice that was being developed by the US military in Vietnam. The M16 was much closer to what it believed it needed under the theories put forward by S.L.A. Marshall, where aiming was no longer necessary and firepower was the answer to all tactical problems.