partypup: Some well placed concertina wire and a few Claymore mines along your perimeter should dissuade all but the most aggressive from violating your “personal space” (which I define as a 100yd perimeter outside of my fence line).
You might also take Breezie up on his suggestion regarding acquisition of a .50 cal. I’d opine against choosing that crappy Russian made DSHK 12.7mm shown in the picture above and opt for the good, old American-made Browning M2 (the “ma deuce”).
That distinctive thumping sound as it fires is much akin to the racking sound of a pump 12ga action: No other sound quite like it and it sends the message very effectively.