Hollow point bullet
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A hollow point is a bullet that has a pit, or hollowed out shape, in its tip, generally intended to cause the bullet to expand upon entering a target in order to decrease penetration and disrupt more tissue as it travels through the target. As a side effect, hollow point bullets can offer improved accuracy by shifting the center of gravity of the bullet rearwards. Jacketed hollow points (JHPs) or plated hollow points are covered in a coating of harder metal to increase bullet strength. A hollow-cavity bullet is an extreme variant of a hollow point where the hollow dominates the volume of the bullet and causes extreme expansion or disintegration on impact.
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[edit] How it works
[edit] Expansion
When a hollow point hunting bullet strikes a soft target the pressure created in the pit forces the material (usually lead) around the inside edge to expand outwards, increasing the axial diameter of the projectile as it passes through. This process is commonly referred to as mushrooming, because the resulting shape, a widened, rounded nose on top of a cylindrical base, typically resembles a mushroom.
The greater frontal surface area of the expanded bullet limits its depth of penetration into the target, and causes more extensive tissue damage along the wound path. Many hollow point bullets, especially those intended for use at high velocity in centrefire rifles, are jacketed, i.e. a portion of the lead-cored bullet is wrapped in a thin layer of harder metal, such as copper or mild steel. This jacket provides additional strength to the bullet, and can help prevent it from leaving deposits of lead inside the bore. In controlled expansion bullets, the jacket and other internal design characteristics help to prevent the bullet from breaking apart. A fragmented bullet will not penetrate as far as one that remains in one piece.
[edit] Accuracy
Where target shooting accuracy is the prime consideration, some bullets such as the Sierra "Matchking" incorporate a cavity in the nose section. This has the effect of lightening the bullet's forward section and shifting the centre of gravity towards the tail of the bullet, so as to give an improved ballistic coefficient, greater down-range velocity retention, and greater resistance to deflection by crosswinds. It must be stressed that match or target hollow point bullets are designed primarily for precision target use, and no consideration is given to their expansion or other terminal ballistic performance on and after impact with human or animal skin, flesh and bone. The United States military, for example, uses a hollow point bullet in some sniper rifles for its exceptional accuracy at long ranges, and the military is of the opinion that the hollow point does not result in significantly different wounds than Full Metal Jacket ammunition in practice.[1] Some hunters, however, have reported good expansion characteristics and quick, humane kills from hollow point target bullets.
[edit] Testing
Terminal ballistics testing of hollow point bullets is generally performed in ballistic gelatin, or some other medium intended to simulate tissue and cause a hollow point bullet to expand. Test results are generally given in terms of expanded diameter, penetration depth, and weight retention. Expanded diameter is an indication of the size of the wound cavity, penetration depth shows if vital organs could be reached by the bullet, and weight retention indicates how much of the bullet mass fragmented and separated from the main body of the bullet. How these different factors are interpreted is subject to the intended use of the bullet, and what constitutes "good" or "bad" performance is subject to disagreement.
[edit] History
- See also dum-dum
Solid lead bullets, when cast from a soft alloy, will often deform and provide some expansion if they hit the target at a high velocity. This, combined with the limited velocity and penetration attainable with muzzleloading firearms, meant there was little need for extra expansion.
The first hollow point bullets were marketed in the late 1800s as Express bullets, and were hollowed out to reduce the bullet's mass and provide higher velocities. In addition to providing increased velocities, the hollow also turned out to provide significant expansion, especially when the bullets were cast in a soft lead alloy. Originally intended for rifles, the popular .32-20, .38-40 and .44-40 calibers could also be fired in revolvers.
With the advent of smokeless powder, velocities increased, and bullets got smaller, faster, and lighter. These new bullets (especially in rifles) needed to be jacketed to handle the conditions of firing. The new full metal jacket bullets tended to penetrate straight through a target and produce little damage. This led to the development of the soft point bullet and later jacketed hollow point bullets at the British arsenal in Dum Dum, near Calcutta around 1890. While these were quickly outlawed for use in warfare, they steadily gained ground among hunters due to the ability to control the expansion of the new high velocity cartridges. In modern ammunition, the use of hollowpoints is primarily limited to handgun ammunition, which tends to operate at much lower velocities than rifle ammunition (on the order of 1,000 feet per second versus over 2,000 feet per second). At rifle velocities, a hollowpoint is not needed for relaible expansion and most rifle ammunition makes use of tapered jacket designs to achieve the mushrooming effect. At the lower handgun velocities, hollowpoint designs are generally the only design which will expand reliably.
Modern hollow point bullet designs use many different methods to provide controlled expansion, including:
- Jackets that are thinner near the front than the rear to allow easy expansion at the beginning, then a reduced expansion rate
- Partitions in the middle of the bullet core to stop expansion at a given point
- Bonding the lead core to the copper jacket to prevent separation
- Fluted or otherwise weakened jackets to encourage expansion or fragmentation
- Posts in the hollow, to prevent clogging of the cavity with materials that may prevent expansion, such as hair and cloth
- Solid copper hollow points, which are far stronger than jacketed lead, and provide very limited expansion even at high velocities
- Plastic inserts in the hollow, which provide the same profile as a full metal jacketed round, but crush on impact to expose the hollows
- Plastic inserts in the hollow to provide the same profile for feeding in semiautomatic and automatic weapons as a full metal jacketed round but that separate on firing while in flight or in the barrel (such as the German Geco "Action Safety" 9mm round)
[edit] Legality
The Hague Convention of 1899, Declaration III, prohibits the use in warfare of bullets which easily expand or flatten in the body.[2] This is often incorrectly believed to be prohibited in the Geneva Conventions, but it significantly predates those conventions, and is in fact a continuance of the St. Petersburg Declaration of 1868, which banned exploding projectiles of less than 400 grams, and weapons designed to aggravate injured soldiers or make their death inevitable. Despite the ban on military use, hollow point bullets are one of the most common types of civilian and police ammunition, due largely to the reduced risk of bystanders being hit by over-penetrating or ricocheted bullets, and the increased speed of incapacitation. In many jurisdictions, it is illegal to hunt game with ammunition that does not expand, and some target ranges also forbid full metal jacket ammunition.
[edit] Winchester Black Talon controversy
In the early 1992 Winchester introduced the "Black Talon", a newly designed hollow point handgun bullet which used a specially designed, reverse tapered jacket. The jacket was cut at the hollow to intentionally weaken it, and these cuts allowed the jacket to open into six petals upon impact. The thick jacket material kept the tips of the jacket from bending as easily as a normal thickness jacket. The slits that weakened the jacket left triangular shapes in the tip of the jacket, and these triangular sections of jacket would end up pointing out after expanson, leading to the "Talon" name. The bullets were coated with a black colored, paint-like lubricant called "Lubalox," and loaded into nickel-plated brass cases, which made them visually stand out from other defensive ammunition. While actual performance of the Black Talon rounds was not significantly better than any other comparable high performance hollow point ammunition, the reverse taper jacket did provide reliable expansion under a wide range of conditions, and many police departments adopted the round. This cartridge was also known as the "Starpoint".
Winchester's "Black Talon" product name was eventually used against them. After a high profile shooting at 101 California Street, San Francisco in 1993, media response against Winchester was brutal. "This bullet kills you better", says one report; "its six razorlike claws unfold on impact, expanding to nearly three times the bullet's diameter"[3] – a gross exaggeration of the actual performance.[4] A concern was raised by the American College of Emergency Physicians, that the sharp edges of the jacket could penetrate surgical gloves, and increase the risk of blood borne infections being transmitted to medical personnel treating the gunshot wound. While possible, there are no recorded cases of such an infection occurring in relation to the Black Talon bullets.[5]
Winchester responded to the media attacks on the Black Talon line by pulling it from their civilian marketing channels, and selling it only through Winchester law enforcement distributors. They also discontinued applying the black Lubalox coating and renamed the line "Ranger SXT." The rounded edges had no function effect on the terminal performance, but addressed the ACEP's concerns about possible dangers to medical personnel.
Even though Winchester voluntarily pulled Black Talon from the civilian market, they were subsequently sued for another 1993 shooting, this one in New York, involving Black Talon ammunition. The suit claimed "negligent manufacture, advertising and marketing of a product that was unreasonably designed and ultrahazardous." However, the court found that "The very purpose of the Black Talon bullet is to kill or cause severe wounding. Here, plaintiffs concede that the Black Talons performed precisely as intended by the manufacturer".[6] Since the bullet was designed to cause rapid incapacitation, and since it performed as expected, the lawsuit was dismissed.
[edit] Terminology
The hollow point bullet, and the soft-nosed bullet, are sometimes also referred to as the dum-dum, so named after the British arsenal at Dum-Dum, near Calcutta, India, where it is said that jacketed, expanding bullets were first developed. This usage is rare among shooters, but can still be found in use, usually in the news media and sensational popular fiction.[7] Recreational shooters sometimes refer to hollow points as "JHPs", from the common manufacturer's abbreviation for "Jacketed Hollow Point".
[edit] Further reading
- History of commercial hollow point bullet molds, going back to the 1890s.
- Premium Rifle Bullets: Who Wins The Toughest Test? Precision Shooter, March, 1996. A comparison test of four different .30-06 hollow point bullets, showing how performance is measured and compared.
[edit] References
- ^ W. Hays Parks, Colonel, USMC, Chief of the JAG's International Law Branch (1985-09-23). Memorandum: Sniper Use of Open-Tip Ammunition. Retrieved on 2007-03-17.
- ^ Declaration III - On the Use of Bullets Which Expand or Flatten Easily in the Human Body. Hague Convention of 1899 (1899-06-29). Retrieved on 2007-03-17.
- ^ Petersen, Julie. "MotherJones SO93: This bullet kills you better", Mother Jones, 1993-09. Retrieved on 2007-03-17.
- ^ Winchester Ranger Talon (Ranger SXT/Black Talon) Wound Ballistics. Tactical Briefs #2. Firearms Tactical Institute (1998-03-01). Retrieved on 2007-03-17. “His absurd claim that this bullet gradually expands as it penetrates simply defies the laws of physics, and is based on fantasy.”
- ^ Hallinan, Joe. "Black Talon: much ado about little", Newhouse News Service, 1995-01-29. Cited in Jeff Chan (1995-03-27). Letter to CNN. RKBA.org. Retrieved on 2007-03-17. “Dr. Stephen Hargarten of Milwaukee, spokesman for the American College of Emergency Physicians stated that to the best of his knowledge no emergency room physicians or medical care providers had ever been cut by the Black Talon round while treating a patient.”
- ^ McCarthy v. Olin Corp., 119 F.3d 148 (2d Cir. 1997)
- ^ "Man who pointed gun at police gets 5 years", Evening Times, Newsquest, 2007-03-09. Retrieved on 2007-03-23. “Police almost shot Steven Bowman, 38, when he was waving a rifle loaded with a dum-dum bullet on a bridge over the M8 in Easterhouse, Glasgow.”
