Guidance

Table 2: specific operations per component

Updated 7 January 2021

Component	Process number	Process	Explanatory notes
1. Barrel	1.1	If the barrel is fixed to the frame (1), pin the barrel to action with a hardened steel pin (diameter >50% chamber, minimum 4.5mm) through the chamber and frame. The pin must be welded (2).	See additional requirements detailed under 1a UK only.
	1.2	If the barrel is free (not fixed), cut a longitudinal slot through the full length of the chamber wall (width >1/2 calibre and maximum 8mm) and securely weld a plug or a rod into the barrel from the start of the chamber (L≥ 2/3rd barrel length).	A plug of at least 2/3rds length of the chamber is to be used on smoothbored arms and a rod at least 2/3rds length of the barrel on rifled arms. The plug/rod should be positioned as close to the breech as possible.
	1.3	Within the first third of the barrel from the chamber, either drill holes (must have a minimum 2/3rds of the diameter of the bore for smoothbore arms and the whole diameter of bore for all other arms: one behind the other, 3 for short arms, 6 for long arms) or cut, after the chamber, a V slot (angle 60 ± 5°) opening locally the barrel or cut, after the chamber, a longitudinal slot (width 8-10mm ± 0.5mm, length ≥ 52mm) at the same position as the holes, or cut a longitudinal slot (width 4-6mm ± 0.5mm from the chamber to the muzzle, except 5mm at the muzzle.
	1.4	For barrels with a feed ramp, remove the feed ramp.
	1.5	Prevent removal of the barrel from the frame by use of hardened steel pin or by welding.
	1a UK only	A longitudinal slot must be cut through the full length of the chamber wall (width >1/2 calibre and maximum 8mm). A plug of at least 2/3rds length of the chamber is to be used on smoothbored arms and a rod at least 2/3rds length of the barrel on rifled arms. The plug/rod should be positioned as close to the breech as possible.
2. Breech block, bolt head	2.1	Remove or shorten the firing pin.
	2.2	Machine the bolt face with an angle of at least 45° and on a surface larger than 50% of the breech face.
	2.3	Weld the firing pin hole.
	2a UK only	Remove part of locking lugs to significantly reduce strength and support.	See pages 32 & 33 of: Specifications for the adaptation of shotgun magazines and the deactivation of firearms, revised 2010.
	2b UK only	In all designs employing a bolt or bolt carrier assembly, these items must either be removed together with all other items and destroyed with a cutting torch, then replaced with shaped pieces of steel plate or tubing and submitted to the Proof House OR a maximum of 50% of the bolt/bolt carrier may be retained to restore the external appearance of the firearm caused by the loss of these major components. They must be securely welded in place with substantial or continuous runs of weld. In the case of one of these weapons being submitted without a bolt/bolt carrier the weapon must have a steel plate or hardened pin securely welded in place to stop the insertion of these components.	See pages 17 & 18 of: Specifications for the adaptation of shotgun magazines and the deactivation of firearms, revised 2010. For SMG’s, providing all conditions in 2b are adhered to, it is permissible for a cocking handle to have functionality and movement if welded to a dummy carrier.
3. Cylinder	3.1	Remove all internal walls from cylinder for a minimum of 2/3rd of its length by machining a circular ring ≥ case diameter.	Remove as much of the internal walls from the cylinder as possible, ideally to the case diameter but this may not be possible without breaching the external wall.
	3.2	Where possible, weld to prevent the removal of the cylinder from the frame, or if impossible, use appropriate measures that render the removal impossible.
	3a UK only	Use annular shaped hard steel blockage welded in place or steel collar. Minimum length and thickness 50% of chamber.	See page 20 of: Specifications for the adaptation of shotgun magazines and the deactivation of firearms, revised 2010.
4. Slide	4.1	Machine or remove more than 50% of the breech face with an angle between 45° and 90°.
	4.2	Remove or shorten the firing pin.
	4.3	Machine and weld the firing pin hole.
	4.4	Machine away locking lugs in slide.	Machine away at least 2/3 of the locking lugs in the slide.
	4.5	Where applicable, machine the inside of the upper forward edge of the ejection port in the slide to an angle of 45°.	This applies to pistols such as Glock, Sig and H&K USP where the barrel locks into ejection port as opposed to lugs within the slide.
5. Frame (pistols)	5.1	Remove feed ramp.
	5.2	Machine away at least 2/3 of the slide rails on both sides of the frame.
	5.3	Weld the slide stop.	Prevent disassembly of metal frame pistols by welding the slide stop. For pistols that do not disassemble in this manner, alternative methods utilising weld can be applied. Blind hole pinning using a tight fitting steel roll pin can be used on pistols only where weld cannot be used due to a dissimilarity of material.
	5.4	Prevent disassembly of polymer frame pistols by welding. According to the National laws, this process can be performed after the checking of the National Authority.	Prevent disassembly of polymer frame pistols by appropriate means, which can include pinning, use of epoxy resin and molecular bonding.
6. Automatic system	6.1	Destroy the piston and the gas system by cutting or welding.
	6.2	Remove the breech block, replace it by a steel piece and weld it or reduce the breech block by 50% minimum, weld it and cut off locking lugs from the bolt head.
	6.3	Weld the trigger mechanism together and, if possible, with the frame. If welding within the frame is not possible: remove the firing mechanism and fill the empty space appropriately (e.g. by gluing in a fitting piece of filling with epoxy resin).
	6.4	Prevent the disassembly of the closing system of the handle at the frame by welding or use appropriate measures that render the removal impossible. Securely weld the feed mechanism of belt fed weapons.	Prevent the disassembly of the firearms major components by welding in accordance with the current UN Firearms protocol. In practice this prevents field stripping. Covers are permitted to be removable providing that all essential components such as breech bolts and carriers are securely welded.
7. Action	7.1	Machine a cone of 60° minimum (apex angle), in order to obtain a base diameter equal to 1cm at least or the diameter of the breech face.	Remove all support on the breech face of the cartridge head.
	7.2	Remove the firing pin, enlarge the firing pin hole at a minimum diameter of 5mm and weld the firing pin hole.
8. Magazine	8.1	Weld the magazine with spots on the frame or the handle, depending on type of arm to prevent removing the magazine.	The term magazine refers to detachable magazines only, NOT internal magazines such as those fitted to K98, etc…
	8.2	If the magazine is missing, place spots of weld in the magazine location or fix a lock to permanently prevent the insertion of a magazine.	It is acceptable to modify a magazine well by welding a pin that would prevent the insertion of an unmodified magazine yet would allow an empty, slotted magazine to be fitted.
	8.3	Drive hardened steel pin through magazine, chamber and frame. Secure by weld.	This section refers to tubular magazines which although may not be readily detachable are still covered by the Regulation.
9. Muzzle loading	9.1	Remove or weld the nipple(s), weld the hole(s).
10. Sound moderator	10.1	Prevent removal of the sound moderator from the barrel by use of hardened steel pin or weld if the sound moderator is part of the weapon.
	10.2	Remove all the inner parts and their attachment points of the moderator so that only a tube remains. Drill holes each 5cm in the exterior remaining tube.	Remove internal components where possible. This would not apply to moderators where baffles are welded in place at manufacture. Holes of at least the bore diameter must be drilled every 5cm longitudinally for the full length of the moderator.
	10a UK only	Flash eliminators, muzzle brakes, sound moderators, combined grenade launcher attachments and any other attachments covered by the Firearms Act fitted to the muzzle ends of barrels must be welded in place to prevent their removal.	See pages 17 & 18 of: Specifications for the adaptation of shotgun magazines and the deactivation of firearms, revised 2010.
Hardness of inserts		Hardness pin/plug/rod = 58 -0; +6 HRC. TIG welding stainless steel type ER 316 L.	The hardness of pins, plugs and rods should be =58 -0: +6 HRC prior to welding. The onus is on the submitter to ensure that the material sourced is of the correct hardness before welding it on the firearm. A sample of each should be supplied for retention by the Proof Authority as spot checks will be carried out by them and other official bodies. TIG welding stainless steel type ER 316 L or equivalent weld as appropriate to the material.
		(1) Barrel fixed to the frame by screwing or clamping or another process. (2) Welding is a fabrication or sculptural process that joins material, usually metals or thermoplastics, by causing friction.