compact and very accurate sniper

[Paul]

Nice little gun TL.
22Lr is a useful round as you say.
In the UK the next best pest control round is the .17 HMR
Ballistically there is quite a difference.
.17 HMR @ muzzle = 250 ft-lbs -- 100 yards = 140 ft-lbs
.22 LR @ muzzle = 155 ft-lbs -- 50 yards = 122 ft-lbs

Just for a interest i'll add these:
Crossbows,(350gr bolt)
High Velocity; 350 fps 98 ft lbs 44 Yards - Effective Range. (Compound Barnett Predator)
Med. Velocity; 300 fps 70 ft lbs 37 Yards - Effective Range. (Compound Barnett Jackal)
Low Velocity; 250 fps 48 ft lbs 30 Yards - Effective Range. (150 lb recurve Barnett Panzer)
Very Low Vel; 200 fps 31 ft lbs 26 Yards - Effective Range. (150 lb. recurve cheap clone)

Not a patch power wise but you don't need a licence for them (yet).