View source for Powerhead (firearm)

{{short description|Specialized firearm used underwater that is fired when in direct contact with the target }}
{{About|the firearm|the water pump used in aquariums|Powerhead (pump)}}
{{Multiple issues|
{{Globalize|article|USA|2name=the United States|date=December 2014}}
{{more citations needed|date=April 2012}}
}}

{{Infobox weapon
| name               = Powerhead (firearm)
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| type               = Underwater Firearm
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| cartridge          = {{plainlist|
* [[.22 WMR]]
* [[Gauge (bore diameter)|12 gauge]] and larger
* [[.357 Magnum]]
* [[.44 Magnum]]
* Others}}
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A '''powerhead''' is a specialized [[firearm]] used underwater that is fired when in direct contact with the target. Powerheads are often used for [[spear fishing]] and against [[shark]]s or [[alligator]]s for sport, defense, or to kill nuisance animals. The term powerhead refers to the firearm-like part of the device; when attached to a shaft to form a [[spear]], it may be referred to as a '''bang stick''' or '''shark stick'''. The spear in question may be handheld or launchable from a [[spear gun]].<ref name=fdlfaq>{{cite web |url=http://www.freediver.net/freedivelist/faqstuff/faq_bangsticks.html  |title=FreeDiveList FAQ |archiveurl = https://web.archive.org/web/20071215231500/http://www.freediver.net/freedivelist/faqstuff/faq_bangsticks.html |archivedate = 2007-12-15}}</ref><ref name=beco>{{cite web |url=http://www.beco-products.com/beco_catalog.htm |title=Beco Inner Space Products On-Line Catalog}}</ref><ref name=atf>{{cite web|url=https://www.cs.cmu.edu/afs/cs.cmu.edu/user/wbardwel/public/nfalist/rr_55569.txt |title=Revenue Ruling 55-569, C.B. 1955-2, 483. |url-status=dead |archiveurl=https://web.archive.org/web/20010719073315/https://www.cs.cmu.edu/afs/cs.cmu.edu/user/wbardwel/public/nfalist/rr_55569.txt |archivedate=July 19, 2001 }}</ref>

==Design==
A powerhead consists of a length of tubing which is the [[Chamber (weaponry)|chamber]] for the cartridge, a firing pin to fire the cartridge, and usually some form of safety pin or latch that prevents firing when it is engaged. The rear of the power head is fitted with some provision for attaching to a spear.<ref name=fdlfaq />

Powerheads are available that chamber a variety of [[handgun]], [[rifle]], and [[shotgun]] cartridges, from [[.22 WMR]] to [[Gauge (bore diameter)|12 gauge]] and larger. [[.357 Magnum]] is probably the most common, as it is fairly powerful yet still compact enough to be used in a spear gun. Large cartridges such as the 12 gauge are generally only used on a handheld spear.<ref name=fdlfaq />

Some powerheads use the cartridge to propel a barbed spear point into the target.  These are generally used on a bangstick for alligator hunting, to secure a line to the alligator to prevent escape.<ref name=beco /><ref>{{cite web|url=http://myfwc.com/gators/public/TO_manual_2007.pdf |title=Alligator Hunting |url-status=dead |archiveurl=https://web.archive.org/web/20110524123203/http://myfwc.com/gators/public/TO_manual_2007.pdf |archivedate=May 24, 2011 }}</ref>

===Purpose of contact-shooting===
[[Bullet]]s are generally designed to work in air, which has a very low [[density]].  The density of [[water]] is roughly 800 times higher than that of air at sea level, and that reduces the penetration of a bullet proportionally.  A bullet might travel a mile (1.6&nbsp;km) in air, but travel no more than a few feet (about a meter) in water. Expanding hunting or defensive ammunition, such as that using [[hollow point bullet]]s, will penetrate even less, as the water is dense enough to cause the bullet to expand. By firing while in contact with the target, a powerhead does not waste energy on traveling through the water, but rather expends all its energy directly on the target.<ref name=fdlfaq />

===How they work===
Although most commercial powerheads use standard [[handgun]] [[ammunition]], such as [[.357 Magnum]] or [[.44 Magnum]], many users choose to use larger caliber ammunition to do maximum damage to the intended target. {{Citation needed|date=February 2012}} A common misconception of how powerheads function is that the [[muzzle flash|muzzle blast]] does the damage, as much high-pressure gas is forced into the flesh of the target. While the gas does do some minimal damage, it is ultimately the penetration of the slug that causes the damage to the target. Most powerheads function just as traditional firearms do, except that it is the spear which acts as the firing hammer.  One commercially produced version used a modified [[.30-30 Winchester]] cartridge case, loaded backwards, with a primed [[.38 Special]] case loaded in its mouth holding the primer.  The cartridge was loaded with the .30-30 case facing outwards, so that the .30-30 case full of burning powder was propelled into the target upon firing.<ref name=fdlfaq /><ref>{{US patent reference |number=4058062 |y=1977 |m=3 |d=21 |inventor=Rhett McNair |title=Powerhead cartridge}}</ref> This system is fast to reload and one of the most effective despite the fact that it does not use a bullet.

===Ammunition issues===
Since most powerheads are designed to use commercial ammunition, which is not designed to be used underwater, the ammunition used must be waterproofed.  A coating of [[nail polish]] or [[varnish]] is commonly used around the primer and case mouth. For [[shotshell]]s, a layer of [[rubber]], such as  a balloon, can be used to seal the crimped front of the shell.<ref name=fdlfaq /><ref name=beco />

==Legal issues==
===Australia===
In Australia they are classed as category A firearms requiring a legitimate reason for issuance of a permit to acquire to a weapons licence holder. When not in use, they must be safely stored in a locked container with ammunition stored separately. Regulations vary between states, with some states permitting their use for defense against sharks only, and not for spearfishing.

===United States===
A powerhead may be considered a firearm under some circumstances.  In the US, the [[Bureau of Alcohol, Tobacco, Firearms and Explosives|ATF]] considers a powerhead a firearm if it is not permanently affixed to a shaft; generally powerheads are sold spot welded to a temporary steel shaft giving an overall length of greater than 18 inches (45&nbsp;cm).  After installing permanently on a spear shaft, the spot weld is cut, and the temporary shaft discarded.<ref name=atf /> Revenue Ruling 55-569, C.B. 1955–2, 483 says:

{{blockquote|text=A device ostensibly designed for submarine spear fishing, but capable of chambering and firing .22 caliber rimfire  ammunition, is a firearm within the purview of the National Firearms Act.  However, such device, if permanently attached to the speargun shaft by the manufacturer, would not be a firearm.|sign=|source=Revenue Ruling 55-569, C.B. 1955-2, 483}}

This ruling is with regard to the [[National Firearms Act]], and not to the 1968 [[Gun Control Act]]. (The National Firearms Act defines 'firearm' as [[machine gun]]s, [[short barreled rifles]], [[Sawed-off shotgun|short barreled shotguns]], and concealable firearms that are neither pistols nor revolvers.) This means that powerheads may still be under the authority of the 1968 Gun Control Act with regard to shipping them and purchase of them from licensed dealers.<ref name=atf />

Laws may also prohibit the use of powerheads in sport fishing.  They are allowed in US federally controlled waters, but many states prohibit their use in state controlled waters. One can be easily in violation of state law despite being compliant with federal regulations.

==References==
{{reflist}}

==External links==
*{{usurped|1=[https://web.archive.org/web/20150723003903/http://www.thejohnharding.com/archives/00000182.htm Wally Gibbins]}} with an eleven-foot tiger shark and 10 gauge shotgun powerhead in 1963. Archived from {{usurped|1=[https://web.archive.org/web/20050206235434/http://www.thejohnharding.com/archives/00000182.htm the original]}} on 2016-07-27.

{{Underwater diving|prodiv}}

[[Category:Firearm terminology]]
[[Category:Underwater firearms]]
[[Category:.357 Magnum firearms]]
[[Category:.44 Magnum firearms]]
[[Category:.22 Winchester Magnum firearms]]