I was half expecting someone to bounce back with that KG (thread 36)......... But hold on to your horses because that may not be exactly correct, especially regarding the proposed UKicon Military spec L4 guns. I am meeting someone v. soon with all/most of the paperwork for this project and it's already been confirmed that during the conversion* all the gas cylinders were removed in any case for another reason to do with 'standardisation' so all this might be answered
* Seemingly, there was the UK Military spec and the CA commercial spec. (I suspect that the CA is Crown Agents who usually dealt with the commercial/export arm of arms trades and all that stuff - that's beyond my depth and pay grade!)