they are spot on as long as its not freezing cold, our kid had the king rat catcher was top for the money but it had the big gas cylinder so not sure how many you get out of a normal one.
if your only shooting up to 5m a pistol might be easier if you a decent shot, bare in mind you cant legally hunt in france with air rifles and if your going on the tunnel you have to check the crack with the co2 or get them over there.