Editing 10mm Auto (section)

==History==
[[File:DCB Shooting Bren Ten & SW 610.jpg|thumb|left|The [[Bren Ten]] (left) and [[Smith & Wesson Model 610]] Classic (right), 1983.]]

When [[Norma Precision|FFV Norma AB]] (now [[Norma Precision|Norma Precision AB]]) designed the cartridge at the behest of Dornaus & Dixon Enterprises, Inc. for their [[Bren Ten]] pistol (a newly developed [[handgun]] with a design inspired by the [[CZ 75]]), the company decided to increase the power over [[Jeff Cooper]]'s original concept. The resulting cartridge—which was introduced in 1983 and produced since—is very powerful, retaining the flat trajectory and high energy of a [[Magnum cartridge|magnum]] [[revolver]] cartridge in a relatively short, versatile rimless cartridge for a [[semi-automatic pistol]].<ref name="BREN-TEN.com Website"/>

Quality control issues plagued early acceptance of the caliber, as a result of rushed production to meet numerous (some even defaulted) pre-orders of the pistol it was originally—as well as then being only—chambered for: the [[Bren Ten]].<ref>{{cite web | url=http://www.bren-ten.com/website/id2.html | archive-url=https://web.archive.org/web/20160405195319/http://www.bren-ten.com/website/id2.html | archive-date=2016-04-05 | title=Dornaus & Dixon Enterprises And The Bren Ten PART 3: The Demise of Dornaus & Dixon And The Bren Ten | publisher=BREN-TEN.com Website | access-date=2015-01-30}}</ref> An example is the peculiar circumstances surrounding the pistol's distribution at its primary release, leading to a number of initial Bren Tens sent to dealers and customers without magazines (the magazines themselves had complications).<ref>{{cite web | url=http://www.bren-ten.com/website/id3.html | title=The Bren Ten In Detail PART 1: Bren Ten Production Modifications | publisher=BREN-TEN.com Website | access-date=2015-01-30}}</ref> The relatively high price of the Bren Ten compared to other pistols of the time ([[Suggested retail price|manufacturer's suggested retail price]] was $500 in 1986, the equivalent of $1,200 [[United States dollars]] in 2021<ref>[https://www.usinflationcalculator.com/ US Inflation Calculator], accessed April 4, 2021.</ref>) was another factor in its demise, and the company was eventually forced to declare [[bankruptcy]], ceasing operations in 1986 after only three years of inconsistent, substandard production. Had it not been for [[Colt's Manufacturing Company|Colt]] making the unexpected decision in 1987 to bring out their [[Colt Delta Elite|Delta Elite]] pistol (a 10mm Auto version of the [[M1911 pistol|M1911]]) and later, the FBI's adoption of the caliber in 1989, the cartridge might have sunk into obsolescence, becoming an obscure footnote in firearms history.<ref name="HoggWalter2004">{{cite book|last1=Hogg|first1=Ian V.|author-link1=Ian V. Hogg|last2=Walter|first2=John|title=Pistols of the World|url=https://books.google.com/books?id=okQH6zFgDtUC&pg=PA88|date=29 August 2004|publisher=David & Charles|isbn=0-87349-460-1|page=88}}</ref>

[[File:Var1bluede.jpg|thumb|left|[[Colt Delta Elite]]]]

Due to media exposure in the television series ''[[Miami Vice]]'', where [[Sonny Crockett|one of the lead protagonists]] had [[Firearms in Miami Vice#Sonny Crockett|used the pistol as his primary signature weapon]], demand for the Bren Ten increased after manufacturing ceased. In the succeeding five years, prices on the Standard Model rose to in excess of U.S. $1,400, and original magazines were selling for over U.S. $150.<ref>{{Cite book |last=Fjestad |first=S. P. |year=1992 |title=Blue Book of Gun Values
 |edition=13th |publisher=Blue Book Publications, Inc |isbn=0-9625943-4-2}}</ref><ref name="Sweeney2008">{{cite book|last=Sweeney|first=Patrick|author-link=Patrick Sweeney (gunsmith)|title=The Gun Digest Book Of The Glock|url=https://books.google.com/books?id=5xdZU0RJqswC&pg=PA60|date=30 May 2008|publisher=F+W Media|location=Iola, Wisconsin|isbn=978-1-4402-2427-0|pages=60–61}}</ref>

The [[Federal Bureau of Investigation]] briefly field-tested the 10mm Auto using a [[M1911 pistol]] and a [[Thompson submachine gun#Model 1928|Thompson Model 1928 submachine gun]]<ref>{{Cite magazine |last=Hill |first=Tracie |date=2008 |title=WHAT'S NEW |url=http://www.nfatoys.com/tsmg/tata/2008_q2/page00006.htm |volume=10 |issue=2nd. QTR., 2008 |magazine=The American Thompson Association newsletter |publisher= The American Thompson Association |page=6 |access-date=2015-01-30}}</ref><ref>{{cite web | url=https://www.americanrifleman.org/content/full-power-full-auto-the-thompson-goes-metric-and-the-mp5-goes-american/ | title=An Official Journal of the NRA &#124; Full Power/Full Auto: The Thompson Goes Metric and the MP5 Goes American }}</ref> as an "urban carbine" before adopting the [[Smith & Wesson Model 1006|Smith & Wesson Model 1076]] in 1990; a short-barreled version of the [[Smith & Wesson Model 1006|Model 1026]] with its slide-mounted decock/firing pin block safety supplanted by only a frame-mounted decocker. A contract was signed with [[Heckler & Koch]] to produce a quantity of the specialized [[Heckler & Koch MP5|MP5]] utilizing the cartridge, designated [[Heckler & Koch MP5#Rechambered variants|MP5/10]] for use by their [[Hostage Rescue Team]] and [[FBI Special Weapons and Tactics Teams|Special Weapons and Tactics Teams]]. Since 1994, both units still field the weapon and caliber to this day.<ref name="HRT"/><ref name="SWAT"/>

The 10mm cartridge was selected for [[Federal Bureau of Investigation]] use after a Wound Ballistics Seminar at the FBI Academy in September 1987, which managed to agree what a good cartridge would do, but couldn't agree if 9mm or .45 ACP could meet FBI requirements.<ref name=":0">{{Cite web |title=FBI's 10mm Pistol {{!}} Office of Justice Programs |url=https://www.ojp.gov/ncjrs/virtual-library/abstracts/fbis-10mm-pistol |access-date=2024-12-21 |website=www.ojp.gov}}</ref> In the same year, an informal test was conducted using a variety of available 9mm and .45 ACP handguns. The test indicated that only the type of 9mm round, described as "147 grain subsonic hollow point round produced by Winchester" had acceptable penetration.<ref>{{Cite journal |date=1987 |title=FBI's 1987 Handgun Evaluation |url=https://www.ojp.gov/pdffiles1/Digitization/113821NCJRS.pdf |journal=}}</ref> The test seemed inconsistent or contradictory to future observers, and it was accused of heavy .45 ACP and American handgun bias.<ref>{{Cite AV media |url=https://www.youtube.com/watch?v=Ux8A4nPJJWs |title=The FBI Said This is the Best Handgun (and Why They're Wrong) |date=2022-07-07 |last=TFB TV |access-date=2024-12-21 |via=YouTube}}</ref> 

According to the latter 10mm report, it was decided: "five shots were fired in each of the 8 penetration tests, providing a total of 40 shots for each caliber or bullet type tested". The first selected was the 9mm described above. The second was a ".45 round, Remington 185 grain hollow point". The Wound Ballistic Workshop participants had a "consensus" that hollow points with "superior penetration" was what was needed.

The 10mm was picked as a "halfway" between the other two options, in terms of size. The "commercial loadings" had "high chamber pressures", which resulted in "heavy recoil" and "muzzle blast". A 180 grain hollow point bullet was "acquired and handloaded to a velocity of 950 feet per second". Later on, factory-loaded ammunition was acquired that met their requirements. During the trials, the 10mm was found to be comparable to the .45 ACP (Not surprising as the bullet weight and velocities were now so similar), but the 10mm was found to take up less space and produce shot groups on targets that were half the size.<ref name=":0" /> 

As the FBI was adopting a 10mm cartridge closer in bullet weight and velocity to the .45 ACP, there was a need for large amounts of newly built ammunition of this type. This requirement was later submitted to [[Federal Premium Ammunition]] for production and further review. This became known as the "10mm Lite", or "10mm FBI" load, or attenuated 10mm, remaining common from various manufacturers today. With some pistol reliability problems increasing in this lighter load,<ref name="Sweeney2008" /> [[Smith & Wesson]] observed that a version of the 10mm case reduced to 22 millimeters in length from the original 25&nbsp;mm could be made with the retained performance parameters of the "10mm Lite". This altered cartridge was named the [[.40 S&W|.40 Smith & Wesson]]. The shorter case allowed use in pistols designed with similar dimensions to those chambered in [[9×19mm Parabellum]], with the advantage that smaller-handed shooters could now have smaller-frame semi-automatic handguns. Colloquially called the "Forty Cal" and other synonyms, this innovation since became a common handgun cartridge among [[Law enforcement in the United States|law enforcement agencies]] and [[Gun culture in the United States|civilians in the United States]], while the parent 10mm Auto remains fairly popular and has shown a resurgence in recent years particularly among hunters.<ref name="BREN-TEN.com Website" />