I personally know of at least two estates where shotgun drives for muntjac still take place. The Police are well aware of it but both estates are untouchable for a number of reasons.
I have seen a roe buck and a fallow doe shot at as they ran through the line on driven pheasant days, on both occasions this drew a mighty cheer from the guns and much ribbing of the offending gun when, unsurprisingly, the animals didn't fall over. To be fair this was several years ago.
I too have skinned and butchered many deer that have shotgun pellets, .22lr bullets and, on one occasion, an air rifle pellet in them.
I'm afraid that those of you who choose to believe this is all done by 'poachers' with illegal firearms are kidding yourselves. Just the same as the headshot deer and shot up roadsigns, the vast majority of these incidents will be a result of people who have legitimate access or employment but choose to behave in an irresponsible manner. Sorry, but it's the truth.