I forget the cross-over distance, but I've seen where subsonic .22LR ammo works better at extra-long ranges.
Basically, when the bullet exits the muzzle, it's traveling at the speed of sound. It has a certain ballistic envelope that keeps the bullet stable. If it's traveling long enough to drop below the speed of sound, it can wobble, change direction or even tumble due to the transition. Subsonic never reaches that speed, so there's no transition.
Subsonic ammo at such distances may also require a slightly higher barrel twist ratio to give the bullet enough spin to avoid wind and other factors interfering with its path.
I don't have any experience doing this, but the things I've read and watched on the subject are interesting. They say the effective range of a .22LR rifle (redundant?

) is up to a mile. If you can get the round on target at that range, why not!
