SOILING IN VIEW

Every good gun cleaning session begins with a detailed visual inspection in which it must be decided which components require which form of clean and maintenance. This begins, of course, with a look into the barrel – virtually the heart of the gun when it comes to accuracy. For a detailed visual inspection of the barrel, optical aids should be used as far as possible, such as a magnifying glass, a speculum, a magnifying angle mirror or even an endoscope. In addition, good lighting is important so as to interpret soiling in the barrel correctly, such as an LED light or a special barrel light.

Now, when looking into the barrel, the experienced gun owner can recognise what types of deposits are lying there. Normally, the inner walls of the barrel glisten with a silver colour; if, however, coloured shadowing is detected, a more intensive cleaning is required. For example, yellowish-red deposits are due to tombac, copper or brass or, even worse, rust.

In most cases, light lead residues are difficult to detect with the naked eye, especially in the case of short guns and muzzle-loaders. Here, using a brush or chemical aids is often the only thing that will help. If a brush is used for the cleaning, underlaying a white sheet of paper is helpful for detecting lead residues; this makes the lead glitter that falls out the barrel easily visible. An unmistakable indication of heavy lead deposits is also the flattening of the lands and grooves in the chamber area – in this case, an extensive clean is unavoidable.

Only after a detailed visual inspection in which it is established which type and what degree of soiling there is, can the appropriate barrel clean be carried out.

In addition to the visual impression of the gun and of the interior of the barrel, a large number of other factors also play a role here, such as: when was the last time the barrel was cleaned? How often has the gun been shot since then? Above all of course, with which ammunition?

According To The Ammunition

An important matter for cleaning the gun barrel effectively and yet protectively is whether lead ammunition or lead-free ammunition was used, as lead residues in the barrel demand a special cleaning. However, even here there are misunderstandings, as different things are often being spoken about without it being clear and even consciously realized.

Lead ammunition refers only to projectiles made completely of lead. Accordingly, lead-containing semi-jacketed bullets or full metal jackets are actually not lead ammunition because, although they have a lead core, they are coated. When it comes to lead removal in the barrel, of primary importance is whether lead comes into contact with the barrel at all and at what temperatures this occurs – as whether there can be lead deposits in the barrel and how strong these are is dependent on this.

The mere classification into lead ammunition and lead-free ammunition is not sufficient, certainly for the topic of barrel cleaning. Here, it is necessary to distinguish between full metal jackets and complete-jacket projectiles, as even when fully jacketed ammunition is used, lead can come into contact with the barrel. The reason is that although the visible part is coated, the base of the projectile is not. Since, when firing, the highest temperatures take effect on the projectile base, the lead can also be fused with this type of fully jacketed ammunition and can settle as soiling in the chamber area as well as, above all, in the first third of the barrel. In contrast to full metal jackets, complete-jacketed projectiles have a completely closed projectile body, with the base sealed off by a tombac lamella – hence, the lead cannot be fused. The same applies to copper-coated projectiles – lead projectiles that are completely coated with a layer of copper by galvanic means.

Another special case is lead projectiles equipped with a gas rear that covers only the projectile base. Here, although the ignition does not cause the lead to be fused, the projectile does leave a certain amount of lead deposits behind.

Lead Ammunition

When using lead ammunition, two different types of deposits can arise: “cold lead grit” and the far more stubborn, genuine lead deposits.

“Cold lead grit” refers to soiling due to lead deposits that emerges in the case of weak ammunition with low projectile speeds, as when pneumatic guns are used, for example. No chemical cleaners are required to remove this relatively loose form of lead grit. Instead, they can be removed relatively quickly and easily with Ballistol Universal Oil and a cleaning brush. Additionally, a minimal lead film is sometimes desirable, as it produces a type of lubrication in the barrel.

It is different with the genuine lead deposits, which emerge when the lead projectile in the barrel is accelerated heavily and builds up additional frictional power in the process due to the spin of the grooves and lands. Here, lead projectiles sometimes heat up to temperatures to over 325 °C, the melting point of lead, causing the lead to start to melt in the barrel and to come into contact with the gun steel. The deposits that emerge are so stubborn that even with Ballistol Universal Oil, they cannot be removed adequately. In this case, a particularly effective solvent such as Robla Solo MIL must be used in order, first of all, to solvate the lead deposits, so that, in the next step, they can be completely removed when cleaned manually with a brush. It should be noted, however, that these stubborn lead deposits mostly emerge only in the case of guns with high projectile speeds of at least 300 m/s, soft lead hardnesses and barrels with narrow

LEAD-FREE AMMUNITION

Lead-free ammunition refers mostly to the heart of the projectile, that is, the projectile core. In most cases, the main components of lead-free ammunition are copper and zinc – although the principal part is always copper. If the copper proportion is 67% or over, it is referred to as tombac. If the copper proportion of the lead-free projectile is less than 67%, the alloy is called brass.

An important aspect of lead-free ammunition is the increased pressure when the bullet is forced through the barrel, which, in turn, leads to increased deposits in the barrel. The reason for this is that lead-free ammunition has a harder projectile core and therefore cannot be deformed as easily. This leads to greater frictional resistance when the projectile is deformed. Since lead-free projectiles are also slightly more sensitive to existing deposits in the barrel, cleaning the barrel is of greater priority if lead-free ammunition is used than if lead-containing projectiles are used. If lead-free is used, more frequent cleaning is recommended in order to ensure the precision of the gun in the long term.

In the case of around 90% of ammunition used in hunting, the projectile surface consists of a copper alloy. In the case of brass projectiles, the projectile deposits in the gun barrel are, in all cases, so stubborn that a special, highly effective cleaner such as Robla Solo MIL is required. In this way, the residues are solvated and subsequently removed safely with a cleaning brush and a cleaning rod.

Nickel-platinized projectiles occupy a special position when it comes to lead-free ammunition, as nickel grit cannot be dissolved chemically and must therefore be removed from the barrel mechanically. Here, a high-quality, suitable bronze brush with correspondingly dense bristles is essential.