A deactivated weapon started life as a service or commercially issued weapon be it a rifle, pistol, sub machine gun, light machine gun, mortar, missile or hand grenade, which for some reason or another has been taken out of service or in most cases has become obsolete.
For a weapon to become deactivated is when it has had most of its major components either removed or cut away leaving the external appearance unaltered. IT CAN NO LONGER FIRE LIVE AMMUNITION.
For example: a bolt action rifle - a manually operated weapon would have to have the barrel slotted down the middle all the way up to the breech, this operation would all so remove the feed ramp, then a hardened case steel pin is inserted in the breech to stop any round (bullet) from being loaded.
In some cases once the barrel as been slotted a steel rod would be inserted down the full length of the barrel and then welded in place, but leaving at least 1 centimetre clear from the front end of the barrel or other wise known as the muzzle clear (for external appearance only).
The bolt face would have to be cut back to at least a 45 degree angle to stop any ammunition being loaded. And various parts of the receiver would also be slotted or cut so that the frame will not take any firing force.
This operation is carried out on all weapons such as pistols, self loading rifles and sub machine guns. Once this work has been carried out, the rifle parts would be taken to a local Proof House.
A proof house is a place where barrels and weapon parts get tested under firing conditions making sure the weapon does not blow up and functions correctly.
There are only two main Proof houses in England that will specialize in this sort of work one is in Birmingham and the other is in London.
When the rifle goes to the proof house, an inspector would have to inspect the weapon and make sure the weapon is incapable of firing any missile, bullet or any other object from its barrel and that all the major functional parts have been rendered incapable and no longer serve there original manufactured purpose.
Once this type of inspection has been carried out, the inspector will then stamp the parts of the weapon with an inspector stamp which proves the weapon has been deactivated and is incapable of firing anything.
Each deactivated weapon will come with it's own certificate of deactivation, which should be kept safe at all times as it legally proves the weapon has been deactivated and inspected by the proof master.
Old specification refers to weapons which were deactivated before October 1995. Weapons deactivated after October 1995 are known as new specification deactivated weapons.
Old specification deactivations allowed for submachine guns and semi automatic rifles to have working actions, which could be fully stripped down to their major components.
Revolvers were allowed to have unblocked cylinders enabling inert ammunition. Under new specification rules, this could no longer be done.
Also under new specification rules, submachine guns and semi automatic rifles had all their actions welded prohibiting cocking or dry firing.