At a PD town, one of the safest rounds to shoot is something like .223 Rem with 50-55 grain frangible bullets or .204 Ruger with 32-40 grain frangible bullets. When they hit anything, they pretty much just turn into small lead fragments. When loading my CZ 527 .223 Rem with soft frangible bullets like the 50 grain Nosler ballistic tip at maximum velocity well over 3300 FPS, sometimes the bullet never reaches the target as it disintegrates on the way to the target due to centrifugal force. If it hits a PD, you get an exploding water bottle sound. Of course I am shooting low over the ground and the bullet will soon hit something and totally disintegrate whether it hits a PD or not. Shooting up into the air is an entirely different matter. As for .22LR, if you miss the PD, it will skip over the ground for a long ways and is actually more dangerous to anything behind the PD. When pellets skip over the ground, they do it for less distance than .22LR. Moderators are legal with airguns, but they are only legal on firearms if going after nongame varmints, and you better prove you were after varmints if caught. The way to "airgun hunt with .22LR" is to use subsonic rounds, and the hardest hitting with the least noise is the Aguila 60-grain Sniper SubSonic. It runs at about 900 FPS out of my CZ 452 American and is no louder than my BSA Lonestar .25 without a moderator, and poSSSibly even quieter. Mainly the tone is different between the two. The SSS is like nothing else out there, and not all standard twist rifles shoot it accurately. I shoot at altitude so I do not need a sea level twist rate. That means it will tumble on impact and has extreme knockdown power on varmint class animals. It is sometimes used by veterinarians as a quiet and humane way of euthanizing terminally ill animals. The SSS does not work well in semi-auto rifles due to the extreme gas leakage from the short case in concert with the looser chamber. The SSS also burns very dirty and will soon foul up a semi-auto action even if the first few rounds cycle the action. I had very bad experience with SSS in a Ruger 10/22, but a Ruger 77/22 shoots it extremely well and very accurately. The SSS shot from standard twist barrels will tumble immediately upon impact with anything and that limits its downrange lethality as it quickly slows down. The hardest thing is finding some as it is always in short supply. It costs about twice of what JSB Exact King Heavy costs in .25 cal. If I have to put down something rather large but keep things quiet, it gets the nod. For birds no good, except for very big ones like a turkey. For something really tough like a porcupine or badger, better than any .25 cal pellet. If you want to get attacked by a badger at a PD town, just try shooting one with your airgun.
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