Hollow point bullet
A hollow point bullet ( English Hollow Point Bullet , HP for short ) is a type of projectile used for long and short weapons with a cavity at the tip of the projectile. This hollow causes the bullet to deform (mushroom) in the shape of a mushroom on impact and to enlarge its cross-sectional area. The expansion can take place up to twice the projectile diameter.
Due to the lower cross-sectional load of a mushroomed bullet (the calculation formula is mass per cross-sectional area ), more energy is transferred to the target medium. This can lead to a complete release of energy, which results in a " plug shot ". In contrast to this, only part of it is released in the event of a penetration, because the emerging projectile retains the residual energy. However, as the cross-sectional load decreases, the penetration power of a projectile also decreases .
The hollowing out causes a much faster and usually stronger deformation than with semi-jacketed bullets, so that the bullet achieves a good effect even at a lower penetration depth (e.g. with small animals), but also has only a low penetration effect.
Bullets with high energy output have a high man-stopping effect . Plug-in shots cause a lower "hinterland hazard" (from projectiles flying further). Bullets with reduced penetration are "shooting range friendly".
In many cases the inside of this cavity is not covered by the bullet jacket, but the lead core is exposed. But there are also variants in which this cavity is filled with a plastic cone or covered by a ballistic hood .
Hollow-pointed bullets originally emerged from the middle of the 19th century , when the round ball to the long bullet made the transition . The purpose of the hollow point was to give the bullet a more elongated shape without adding weight. The greater target ballistic effect was recognized later .
Another advantage of the hollow point shape is that the bullet's center of gravity shifts towards the bottom of the bullet, which improves the ballistic properties . For this reason, and because the rapid deformation minimizes the risk of ricochets and bullets , hollow point ammunition is very popular with sport shooters and hunters.
Basically, the mushrooming of a bullet also depends on the speed and the resulting energy output. A rule of thumb is that it takes at least 300 m / s to expand a hollow point bullet. Since such a speed cannot always be reached from a handgun , ammunition is often provided with notched jackets in the area of the projectile tip in order to ensure safe expansion even at low speeds.
In order to achieve a compromise between penetration and man-stopping effect, the so-called Hydra-Shok ammunition was developed for the US police , in which a lead pin is located inside the cavity so that the bullet still has a point after it has "mushroomed". Another special form are hollow point bullets, in which the bullet jacket also covers the inside of the hollow point, which leads to only a very small deformation in the target.
See also
literature
- Beat Kneubuehl : Bullets . Volume 1: Ballistics, accuracy, mode of action . 2nd Edition. Motorbuch Verlag, Stuttgart 1998, ISBN 3-7276-7119-X .
- Beat Kneubuehl: Bullets . Volume 2: Ballistics, effectiveness, measurement technology . Motorbuch Verlag et al., Stuttgart et al. 2004, ISBN 3-613-30501-1 .
- Beat Kneubuehl (eds.), Robin Coupland, Markus Rothschild , Michael Thali: Wundballistik. Basics and Applications . 3rd completely revised and expanded edition. Springer Medizin Verlag, Heidelberg, 2008, ISBN 978-3-540-79008-2 .
- Manfred R. Rosenberger: weapons and ammunition used by the police . Motorbuch Verlag, Stuttgart 2002, ISBN 3-613-02246-X .
- David Harding (Ed.): Weapons Encyclopedia. From hand ax to cruise missile . 2nd Edition. Motorbuch Verlag, Stuttgart 1995, ISBN 3-613-01488-2 .
- Markus Stappen: Police bullets and other deformation bullets, special tape for ammunition in police use and commercially available ammunition , Verlag Sascha Ulderup, 2015, ISBN 978-3-9817001-2-1 .
