John, wouldn't surprise me, most things in UK are illegal or as some say "highly illegal" whatever that means. Basically if you walk out your front door you must be doing something wrong. Seriously, I suppose it is propelling a projectile by a type of "charge" albeit not enough to hurt a cockroach. You can't own one of those but you can buy a bow.
Baz
BE AN INDEPENDENT THINKER, DON'T FOLLOW THE CROWD
For you "Death Wish" kids.A 1950's 38mm calibre,Austin MAGIC Pistol.Powered by acetylene,it will shoot, a ping-pong ball- type missile 60ft-and a tongue of flame 8ft!!Forget about,"you'll shoot your eye out"-this baby will burn the house down!
https://i.imgur.com/5TbyzMv.jpg