I like the Remington .22LR subsonic hollow point rounds. I use them for squirrel hunting in my Ruger 10/22. I think the lower noise signature helps to not scare the animals as badly. The squirrels seem to come back out sooner. These rounds will function in auto-loaders and do not give up any noticable preformance when compared to conventional rounds on squirrels. These rounds eliminate the sonic "crack" that travels much further than the muzzle blast. From a distance, especialy in the woods, the sonic crack is what is most noticable about the noise generated by a firearm.