A very staged event of course but by default here, that's the nature of the beast, especially in the UK.
It's a very evocative sight and sound, a Vickers MMG opening up. We used to set a Vickers gun up in a gun-pit, covered and almost out of sight on the field firing ranges at Salisbury Plain. It'd be on the first day of live firing for the current Sustained Firing course (the SF Course) when they'd set up the L7, MAG-58 GPMG's. Nice cold morning and once they'd set the guns up we would stop and uncover a Vickers or two and give a short history lesson of the effects of sustained and overhead fire as battle inoculation.
Then let them loose on fixed lines at the 'enemy front line' or 'observed enemy activity' a mile or so away. A great show with the steam meeting the early morning mist. Big cheer from the young SF crew and we'd let a few use up the last belt. Nice to see the 1:5 tracer go down the range and 10 tracer at the end of the belt.
A true history lesson. I wonder of they still do it. To be honest, the SF gun crews with their SF GPMG's were VERY good.