Was thinking the same thing... Had an old gent where I grew up that did not need a scratch box or call, used his mouth to call the birds in. His boomstick of choice was a Marlin 39A.... all camo'd up... He did not miss, and took them way before I ever thought possible with my 12 gauge.... Also...
Also, speak to your local Green Jeans and make them aware of the situation. We have them checking our acreage regularly, and after 2 arrests word got around.
When folks kept duck hunting our swamp, I removed the valve stems from their vehicles and had them towed. 2 rounds and all done for.
Can’t do it now, but a milk jug of used motor oil with a pinhole in it, thrown in the lake, will get rid of them.
The oil on their pelt drives them bananas, and they will find another home.
I always get an itch when this topic comes up.
Physics dictate the sub vs supersonic equation. Are we discussing quiet vs quieter?
Speed has to stay below 1050 fps to avoid the dreaded super crack, so the best way to up the ft/lbs of kinetic energy delivered to the target is to up the weight...