Small Arms Survey examines firearm marking techniques


The Small Arms Survey says states should do more to ensure the correct marking, and therefore tracing, of weapons.

The Small Arms Survey is an organisation advocating the control of small arms proliferation. The organisation, in a new report, says weapons marking is an essential part of record keeping and allows authorities to track firearms. This, they say, is just one step in the process of curbing the illegal trade in small arms.

The Survey notes the United Nations adopted a Firearms Protocol against the illicit manufacturing of firearms in 2001 and in 2005 adopted an International Tracing Instrument agreement aimed at enabling states to trace and identify small arms.

The protocol recommends that when a firearm is manufactured, it should bear the name of the manufacturer, the country or place of manufacture and the serial number. When firearms are imported, the year of import and country of import should be marked on the weapon. In addition, when firearms are transferred from government stocks to civilians, they should be marked to reflect this. This should speed up the process of solving gun-related crimes and shorten the time it takes to trace the flow of firearms across borders.

The most common marking methods are stamping, dot peen or micro-percussion, mechanical engraving through scribing and laser engraving.

The actual process of firearm marking involves adding data by deforming or removing material. Deforming methods, such as stamping and dot peen, apply marks through impact or compression. Material removal, on the other hand, refers to carving, cutting, ablating, melting or burning.

Stamping remains the most common marking method, mostly due to its low cost. The most popular techniques are press marking and roll marking. Press marking is faster and more economical than roll marking and involves either impact presses that add marking with a single stroke, or compression presses that slowly deliver pressure without a sudden impact. This offers reduced stresses for the parts being marked and gives less wear on the machine. Unlike impact press marking, any shape can be compress marked.

For components that are fragile, roll making becomes a good stamping option as data is rolled on to a part one character at a time, minimising the pressure and contact area needed.

Dot peen or micro-percussion uses a hardened stylus to imprint individual dots on a part to create alphanumeric characters, just as a dot matrix print prints using thousands of small dots of ink. Dot peen machines can mark up to five characters per second on flat, concave or convex surfaces. Dot peen systems have many strengths, such as low cost, high speed, efficiency, flexibility and the low stress on components. However, the system is noisy and of relatively low quality.

An alternative to deforming material is to remove it. Mechanical engraving with a scribing machine (which uses carbide or diamond cutters or hardened pins) is a relatively widespread practice that involves less aggressive action than stamping. Another engraving method is to use a laser beam, which avoids physical contact and is good for fragile and very small parts. The two most important forms of laser marking use either a diode-pumped laser or fibre laser, the latter of which is more expensive but the equipment has a longer lifespan. Laser engraving is increasingly the marking method of choice among arms producers because of its precision, speed and lack of physical contact.

Another marking method utilises moulding, which is becoming more popular with the extensive use of plastic polymers in firearms. An alternative to stamping or engraving is electro-chemical marking, which involves the use of a stencil that transfers the mark through an electrolyte fluid. However, it only works with electrically conductive surfaces.

Because modern firearms are built using a number of different methods, it is possible for a single firearm to require several different marking methods.

An important consideration is the recoverability of marks after intentional defacing or alteration. Only marks applied to metals are capable of being recovered (although in only 50% of cases), since marking metal alters its physical structure as a whole. As a result, firearms with plastic frames often have a metal tag with serial number on it.

According to Small Arms Survey, the dot peen system takes 7-8 seconds to mark 20 characters on a metal plate while engraving takes 16 seconds and laser engraving takes 4 seconds. Regarding price, stamping is cheapest, with an entry-level machine costing $5,500-$6,800; a dot peen machine costing $6,800-$9,000; an engraving machine costing $16,000-$19,000 and a laser engraving machine costing $41,000-$48,000.

For a marking method to be effective, it needs to avoid damaging the firearm, be practical to use, be able to apply marks to several components, result in a readable, durable and possibly recoverable mark, and have an acceptable cost per unit produced or marked.

When choosing a marking method, there are a number of factors to consider: cost; quantity of firearms to be marked; the type of firearms and material, and relevance of recoverability of altered marks. Small Arms Survey recommends at least one mark on a firearm be made using the stamping or dot peen process as this assists in recovering altered marks. The organisation suggests a laser marking system for manufacturers with a high budget; a dot peen system for those with a low budget and an engraving system for manufacturers who make firearms primarily for the civil market.

Canada is one of the first countries to attempt implementing an intensive and strict firearms marking law in line with the UN protocols, but has met with serious setbacks. New regulations were created in 2004 and scheduled to go into effect in April 2006, the Globe and Mail reports. However, the regulations have been deferred several times, most recently until 2012.

At the moment, Canadian law requires firearms to only have a serial or identification number, but the proposed regulations require markings indicating the gun’s origin and date of import, the Globe and Mail reports. This would affect the cost of purchasing a firearm and would complicate the importation of firearms into the country.