Kvalitetsparametre for haglammunition:En undersøgelse af spredning og indtrængningsevne som funktion af haglenes størrelse og form

• Main Authors: Hartmann, Poul, Kanstrup, Niels, Asferg, Tommy, Fredshavn, Jesper
• Format: Book
• Language: Danish
• Published: Danmarks Miljøundersøgelser 1999
• Subjects: The Muzzle; National Environmental Research Institute
• Online Access: https://pure.au.dk/portal/da/publications/kvalitetsparametre-for-haglammunition(39230321-2ae7-42ee-8497-b464b548a632).html; http://www.dmu.dk/1_viden/2_Publikationer/3_fagrapporter/rapporter/fr295.pdf

This report presents the results of an investigation aimed at identifying some basic properties of shotgun ammunition that may possibly affect the risk of crippling game. The investigation is a follow-up on the Danish Wildlife Administration Council Action Plan for prevention of crippling game recommending the exclusive usage of quality ammunition for hunting and the introduction of standard specifications for shotgun ammunition. Following these recommendations, a preliminary investigation of two materials currently used for the production of shotgun pellets, steel and tungsten-polymer (matrix shots), was carried out by the Danish National Environmental Research Institute in co-operation with the Danish Hunters' Association and the Danish Army Combat School. The aim of this pilot study was to provide substantial data to elucidate the effect of varying basic, physical properties such as size, weight, and form on the dispersion and penetration performance of pellets. A series of test shootings made on paper sheets and gelatine dry-plates clearly shows that the size and form of pellets are decisive factors for the shot performance. Many separate tests show that variations in these factors account for an essential part of the overall variation in both dispersion and penetration of pellets. The smaller the pellets are, the bigger is the mean dispersion, which is, of course, due to the fact that big pellets are heavier than small pellets. However, the variation of the dispersion is large for all pellet sizes, and the size as such explains only a minor part of the total variation in the dispersion of pellets. The bigger and heavier the pellets are, the deeper is the mean penetration, which is due to the fact that at identical muzzle velocities big, heavy pellets have a larger impact than small, light pellets. Due to their higher density, tungsten-polymer pellets (matrix shots) will penetrate deeper than steel pellets of the same size. Variations in the size and weight of pellets explain most of the overall variation in penetration performance. The more deformed a pellet is, i.e. differing from a perfect spherical form, the farther away from the shot cloud centre the point of impact will be. However, variation in the degree of deformation only explains a very small part of the overall variation in the dispersion pattern. The more deformed a pellet is, the lesser the penetration into the gelatine. Variation in the degree of deformation basically explains the variation in the penetration performance of both steel and tungsten-polymer pellets. However, due to their higher density, tungsten-polymer pellets will penetrate deeper than equally deformed steel pellets. The closer the point of impact of a pellet is to the centre of the shot cloud, the deeper the mean penetration into the gelatine will be. This effect can be explained by the above fact that big, heavy, non-deformed pellets do on average have a smaller dispersion rate and a better penetration performance than small, light, and deformed pellets. Thus, the mean impact energy will decrease proportionally to increasing distance from the centre of the shot cloud. The dispersion of pellets is primarily determined by the choke. The test shootings demonstrate that the pattern is especially affected by the size and weight of the pellets and that the degree of deformation is of minor importance. The penetration performance is primarily determined by the weight and size of the pellets, but in this respect the degree of deformation is also an essential factor. Test shootings demonstrate that the penetration into the gelatine of non-deformed pellets is identical for peripheral and central pellets. In contrast, a certain proportion of deformed pellets in a shotgun cartridge will, although slightly, reduce the penetration performance of pellets proportionally to increasing distance from the centre of the shot cloud. The test shootings have proven that the gelatine dry-plate method provides a far more detailed basis for analysis than the paper sheet method. The gelatine dry-plate method allows for recovery of each individual pellet and a subsequent analysis of its size, weight and degree of deformation compared to the pattern and penetration performance. However, registration of gelatine shootings are far more laborious than paper shootings. Random sampling of a few shotgun cartridges available on the Danish market does not immediately justify that the introduction of standard specifications for variation in the size and form of pellets will significantly reduce the risk of crippling. That this is the actual fact should, however, be substantiated by a major check of a wide range of shotgun cartridges available on the Danish market. The absolute effect of variations in size, weight, and deformation of pellets can only be assessed when more information on the causes of crippling is made available. A decisive factor will be to thoroughly examine to which extent crippling is caused by the 33 - 40% of pellets hitting outside a diameter of 75 cm. If crippling is proved to be mainly caused by peripheral pellets, it will be crucial to initiate investigations of the whole shot cloud, i.e. not only the pellets in the centre of the pattern, but also the peripheral pellets. Further recommendations will be to examine additional factors which may affect the shotgun cartridge quality like for instance the consistency of the pellet muzzle velocity and the influence of temperature on the muzzle velocity as well as the importance of the shot cup design on the overall shot performance.