Some people who go shooting, shoot at all kinds of things, anything that moves. Or set up targets.
Many don't have permits. Around here there are regular cases of groups of shooters going on to private property, without the owners knowledge. The ones that get caught are usually from Sydney.
Heaps of them have their vehicles set up with a huge number of spotlights. Often they get away, leaving the results of their nights outing, all kinds of dead animals including farm animals.
It's a regular thing here to hear the shots at night, but I've also heard them in the daytime.
So yes, shooting is high up on my list of what might have happened.