Mike,
Good to hear from our fellow "gunners" in far off places. The "click" sound switching from safe-semi-auto/burst on military or the very very few civilian owned "registered class 3" rifles is the same level of resistance and audible "click" which occurs on the much more common safe-semi rifles owned here in the US. The mechanical difference is a lengthened guide channel for the safety detent, so the selector can rotate further. The machining on the body of the selector is cut a bit different to permit the auto sear to toggle onto the hammer spur and the disconnector to be held out of the path of the hammer. As you might have guessed, the commonly owned civilian rifle receivers are not machined to accept the auto sear assembly, and should not have a military trigger, hammer, disconnector, or bolt carrier assembly. Hope that answers your question. Happy shooting.