1. Field of the Invention
The invention concerns the marking of the barrel of a firearm, in particular a pistol, a rifle, or a carbine, in particular in correspondence with the introductory part of Claim 1.
2. Description of Related Art
Upon passing through the barrel of a firearm, deformations are applied to the projectile by means of the contact with the inner surface of the barrel, which may serve to ascribe to a projectile the weapon from which it was shot. This possibility has been used over many years in forensics, but as a result of the arrangements of the inner surface of the barrels which are better and better, more and more precise, and thus which have been provided with fewer variations from weapon to weapon, it has resulted that differences of that sort were more and more difficult to determine. For several years, there have now been barrel cross sections which no longer consist of grooves and lands, as was previously the case, but rather have a polygon cross section and are referred to as “polygonal barrels” for short. Since the relative position of the polygon changes continuously along the axis of the barrel, a rotation of the projectile occurs around its longitudinal axis.
The transitions between the single, straight polygon segments are rounded off, and within that context, an equalization occurs with the cross section of the projectile in such a way that the entire cross section surface of the barrel corresponds to the cross section surface of the projectile. Within that context, the caliber measurement is determined with an even-numbered polygon (the polygons that are most used are hexagons) between two linear segments that are opposite each other, and the arched segments consequently lie “outside” of the area that is determined by the caliber. Consequently, the “caliber” circle is in general the inner circle of the linear-running polygon segments. These polygonal barrels are produced through the cold working of a barrel blank over a mandrel which has the desired cross section. The barrels that are formed in that way are then so indistinguishable from one another that in general it is not possible to ascribe a projectile that has been fired to a given barrel, or to rule out a given barrel. With regard to forensics, this represents a considerable disadvantage.
On several occasions, there have been and there are proposals in order to equip conventional barrels with grooves and lands with markings that permit such an ascribing in complete independence of the barrel. In that regard, reference is made to U.S. Pat. No. 6,796,073, to US 2001/0029690, to U.S. Pat. No. 4,175,346, and to AT 402 702. The contents of these documents are incorporated by reference into this present application for the countries in which that is legally possible.
The methods that are cited in these documents for the applying of markings are completely unsuitable for polygonal barrels. A need consequently exists for a corresponding marking and a method for its application.
It is the problem of the invention to provide such a method or a marking that is received through it. Within that context, the quality of the barrel may not be compromised, and the costs of the manufacturing should not noticeably increase.
USPTO Backgrounds
USPTO Backgrounds