[John O]

OP->Some targets will be 30 yards and some might be 150-200 yards.

If he's shooting .223 and at those ranges at night, I don't think neighbors are a problem and most people with real gardens already use an electric fence.

No matter how far away the neighbors are, he still has neighbors. (unless perhaps he lives on an island). Putting up a fence and just letting the varmints live just moves the problem to his neighbors' land.

Around here "real gardens" are several acres and most do not have electric fences.

[Errant]

If you're really interested in protecting your garden get an electric fence. If you don't, you will eventually sustain quiet a bit a damage or total loss. It works on everything but crows.

Controlling damage to large fields from marauding wild hogs is a whole different animal.