Seriously....
We've talked about UK gun laws quite a lot in here, so here are the bare facts:
http://www.met.police.uk/firearms-enquiries/index.htm"Firearm certificates differ from shotgun certificates in that each individual weapon held on the former, needs to be authorised for its use. It is for this very reason that an applicant is required to satisfy the Chief Officer of Police, of his reason for requiring that weapon, for that purpose.
...The holder of a firearm certificate has a far more limited flexibility when it comes to possessing firearms. It is a requirement of the Firearms Acts that such certificate holders specify their reason for each and every firearm they require.
What is more, the police must be satisfied that the weapons requested, are suitable for the reasons stated. For instance, it would not be acceptable to request a .303 rifle for controlling rabbits!"
Prohibited weapons:
"Section 5 (1)
(a) any firearm which is so designed or adapted that two or more missiles can be successively discharged without repeated pressure on the trigger.
(ab) any self-loading or pump-action rifled gun other than one which is chambered for .22 rim-fire cartridges.
(aba) any firearm which either has a barrel less than 30cm in length or is less than 60cm in length overall, other than an air weapon, a muzzle-loading gun or a firearm designed as signalling apparatus.
(ac) any self-loading or pump-action smooth bore gun which is not an air weapon or chambered for .22 rim-fire cartridges and either has a barrel less than 24 inches in length or is less than 40 inches in length overall.
(ad) any smooth bore revolver gun other than one which is chambered for 9mm rim-fire cartridges or a muzzle-loading gun.
(ae) any rocket launcher, or any mortar, for projecting a stabilised missile, other than a launcher or mortar designed for line throwing or pyrotechnic purposes or as signalling apparatus.
(af) any air rifle, air gun or air pistol which uses, or is designed or adapted for use with, a self-contained gas cartridge system.
(b) any weapon of whatever description designed or adapted for the discharge of any noxious liquid, gas or other thing.
(c) any cartridge with a bullet so designed to explode on or immediately before impact, any ammunition containing or designed or adapted to contain any such noxious thing as is mentioned in paragraph (b) above and, if capable of being used with a firearm of any description, any grenade, bomb or other like missile, or rocket or shell designed to explode as aforesaid."
continues....