Twin wheel (ammunition)

The twin wheel is a Munition of Plomb intended for the compressed-air weapons. The form in " jupe" of its back part, out of soft metal, the sealing with the gun of the weapon ensures, because it tends to widen under the pressure of the compressed air. The projectile is thus propelled with the maximum of swiftness. Lead being self-lubricating it slips into the gun of the weapon by avoiding the wear of this last. One owes with this metal the current name given to the twin wheels: " plombs".

The twin wheels more current are in gauge 4.5mm (gauges .177) or 5.5mm (0.22 gauge). The twin wheels of 4.5mm are used for the shooting of competition to 10 meters, the gun and the air gun. These weapons, like those of leisure or hunting, give emission velocities ranging between 100 and 350 m/s according to their power.

These ammunition are of the interest to be inexpensive and of being able to be recovered to be used for manufacture of new twin wheels. This manufacture is operated by Matriçage because reduced dimensions of these ammunition (a few millimetres) do not authorize a direct moulding. The disadvantage presented by this ammunition are:

a tendency to rebound to see bursting at the time of shocks with certain surfaces, which makes it really dangerous when it is drawn by powerful rifles.
Toxicity of the material lead, and its additives or impurities if necessary (Arsenic, Antimony)
the loss in the environment of million twin wheels, because actually little of these lead is recovered and re-used.
In the event of accident; with the difference of the brass or copper ammunition for example, the wound also causes a poisoning by the particles of leads which the impact releases in organic fabrics.
the drives on target fixed on a tree, in outside are current. The lead driven in wood or the bark will be transformed into toxic lead vapor if wood then is burned or machined.

The toxicity of the twin wheels with respect to the organization is extremely reduced to see even negligible: their use in the compressed-air weapons does not lead to rises in temperature being likely to cause the harmful vapor release. Simple precautions of cleaning of the hands after handling are enough.

Some prefer the coloured darts with plumeau to them, which make it possible moreover to allot the success of a shooting to the good shot when several gunners draw on the same target. However these darts are at the same time less precise than the twin wheels and more destroying for the guns because they cause a premature wear of the latter.

It should be noted that there exist also formed twin wheels of a plasticized skirt and a more or less hard metal head such as aluminum. Improving the sealing in the gun, these leads are especially intended to improve the effects with the target: perforation, impact speed.

See too

Toxicity of the ammunition

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