OK, to answer the questions on 22s - No, subsonics do not ricochet any more than high speeds. A ricochet is a 'glancing' off something, and when your bullets ricochet they have glanced off something. Sometimes you hear it 'whine' away and that's caused by the flight of the bullet post impact, but most often you do not hear a bullet ricochet.
It does not matter if the bullet is a bb, cb, 22 short std vel or high speed, hp or rn, 22long or 22 long rifle in any velocity range or bullet configuration - if your bullet hits the target in such a way as to 'glance' off, it will ricochet. When ya don't get a ricochet is when the bullet imbeds in the target or passes through (that's a pass through, not a ricochet).
The area you hunt in sounds fabulous for furry critters and with the nearest house 500 meters distant you should not have a concern about ricochets creating a danger to your neighbor's homes. Understand please that a ricochet of one object glancing off another is not the same as a beam of light reflecting off a polished or mirrored flat surface; with light, the angle of incidence (approach) equals the angle of reflection and may even be brighter. A bullet that ricochets off a object, say a tree trunk or branch, has already spent most of its energy on impact and has lost both its direction and trajectory. It will not travel very far at all. You can skip a 22 slug (round nose works best) off a smooth pond and have it hit again within about 25m, and that's it for the slug, period. Almost a typical ricochet. Not much of an effect, really. But to think of one of your ricochets traveling 500m and strike a neighbors house - no. Thank you very much for the concern and for being so neighborly but I doubt you need worry.
Can you shoot any of the shorter 22 rounds through a 22lr bolt action - sure, although you may have to load them single shot and then clean the chamber after you shoot the shorties to make sure a lr chambers properly but yes you can, it is a lot of fun.....
A subsonic 22lr is a rilfe cartridge and it will killya, period. It ain't no pellet gun son. You can get some whoppin' powerful big bore pellet rifles but a 22lr is a rifle cartridge and dangerous to over 1 mile. I have taken predatory wildfowl with 22 subsonics at distances to 135m and coyotes at near the same. Subsonic 22lrs were designed with a purpose in mind and it wasn't keeping the neighbor hood quiet and not disturbing your neighbors whilst you are laying waste to the local ground squirrel population. FYI - you can do just as well with 22lr standard velocity in many instances as with the subsonics - same weight bullet and same velocity (below speed of sound) in most instances - and many forget that the standard velocity was the original target round before they had to develop new ones.
Regarding your charting of cartridge power - yeah, that's pretty accurate. Most ammo companies don't measure impact energy at distances with something like a ballistic pendulum, they figure it out with a computer program that calculates this, that and the other thing but often fails to consider the effect of the impact of a properly designed bullet at or near the end of its trajectory. They may state that the bullet will only have 'x' amount of velocity/energy based on the initial velocity but they don't usually take into consideration that it may take only a small amount of residual energy to cause considerable damage or even death. I'm not talking of shooting a bullet straight into the air and measuring the effect on the way down as the bullet yaws and tumbles, I mean a 'missed' shot trajectory that might peak at 2-300' elevation or better and maintains its stability. As that slug starts its trajectory of descent it maintains or possibly gathers energy when combined with the force of gravity. It is not as much as it was at the muzzle but it can ouch ya seriously or kill.
If you're shootin' a ground squirrels or chipmunks or other vermin when they are near rocks or stumps or the like I do not believe you should be as concerned as you are over other ricochets toward your neighbors homes. However, there is some danger for you - a ricochet off a flexible object may send the slug right back in your direction - you can hear those go 'flup', flup' 'flupping' by.
You can test this out yourself to see how much some of your slugs ricochet - use some flat rocks off which you can angle your shots into some dirt and you should discover that your slugs do not ricochet either a great distance or with great force. HTH. Mikey.
