If not going to reload I would do the 17HMR. A box of ammo will last awhile if you do not do much shooting. It will do 150m with out to much drama. Same with 22mag. Simple and easy. Finding the ammo that works may take a bit of patience but that is for all rifles.
For a lot more speed the little 17 hornet is wonderful. Louder than a 22 mag but far less than a 223. I have down loaded it to 1900fps but you really need a very frangable projectile at that low velocity. Even the Vmax does little at this speed. The 22 hornet is another favourite of mine and I now have a little 30gn round nose soft point that just destroys itself at low velocity.
The 222 and 223 can be down loaded to the 22Hornet velocity but again the projectile needs to be very frangable. Not much of a win when using a short light projectile as the jump can destroy accuracy. I have a 55gn deep hollow pointed projectile which is a bomb at low velocity so I have that figured out. I still had some of my low velocity 223 rounds with a standard 55 gn Winchester soft point and shot a feral cat on the week end. Just went straight through and that was at less than 10 metres.
Bill
Bill