This link will help you. http://wingedsoldiers.co.uk/sas-malaya.html
The SAS was reformed for Malaya after having been stood down at the end of WWll. A friend of mine was a patrol comdr with SAS .. he said they did deep jungle patrols for 3 months at a time with a weekly resupply by parachute drop. They were 15 men patrols allocated into 3 three man patrols, an officer, sr nco and 3 aboriginals that carried the wireless set, batteries and their own food (they could not eat the military rations) there was also a Sarawak tracker. The patrols could call on reinforcements by parachute when needed
I have read that the Brits used the Browning A5 12 ga shotgun in Malaya as well. Not cut down, but just as it came out of the box.


















































