Duty Arms Index
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Colt AR-15 vs Colt M4 Carbine

Which U.S. law enforcement agencies issue each, by state. Colt AR-15 appears at more agencies in the index (75 vs 52). 12 agencies list both (for example as primary and backup or authorized options).

Data coverage: Based on 510 agencies in the Duty Arms Index with a current, sourced rifle entry. Generations and optic-cut variants are combined per model family. Counts include only current entries with a public source; agencies not yet in the index, or without a sourced entry for this item, are not counted, so treat shares as a picture of the Duty Arms Index, not of every U.S. agency. Data last updated Oct 10, 2026.

Colt AR-15 (model photo)

Colt AR-15

5.56x45mm / .223

Agencies (any current entry)
75
As primary issue
61

14.7% of 510 agencies with a sourced entry in this category.

Colt AR-15 Sporter SP1 Carbine shown. Photo: M62, CC BY-SA 3.0, via Wikimedia Commons. Model photo, not the agency's own firearm.

Colt M4 Carbine (model photo)

Colt M4 Carbine

5.56x45mm / .223

Agencies (any current entry)
52
As primary issue
26

10.2% of 510 agencies with a sourced entry in this category.

M4 shown with M68 (Aimpoint) optic. Photo: Photo Courtesy of PEO Soldier, Public domain, via Wikimedia Commons. Model photo, not the agency's own firearm.

By state

StateColt AR-15Colt M4 Carbine
Arizona—Paradise Valley Police Department
CaliforniaAlameda County Sheriff's Office, Arcata Police Department, Atwater Police Department, Barstow Police Department, Bear Valley Police Department, Beaumont Police Department, Belmont Police Department, Blythe Police Department, Campbell Police Department, Carmel Police Department, Cathedral City Police Department, Chowchilla Police Department, Clayton Police Department, Clearlake Police Department, Cloverdale Police Department, Corona Police Department, Covina Police Department, Cypress Police Department, Dinuba Police Department, El Centro Police Department, Eureka Police Department, Exeter Police Department, Folsom Police Department, Gardena Police Department, Glendora Police Department, Grover Beach Police Department, Hemet Police Department, Hillsborough Police Department, Humboldt County Sheriff's Department, Inyo County Sheriff's Department, Kensington Police Department, Kerman Police Department, La Habra Police Department, Lodi Police Department, Los Alamitos Police Department, Mammoth Lakes Police Department, Marina Department of Public Safety, Marysville Police Department, Montebello Police Department, Newark Police Department, Placentia Police Department, Pomona Police Department, Port Hueneme Police Department, Rohnert Park Department of Public Safety, San Ramon Police Department, Sand City Police Department, Santa Barbara County Sheriff's Office, Santa Clara County Sheriff's Office, Santa Clara Police Department, Sausalito Police Department, Seal Beach Police Department, Seaside Police Department, Selma Police Department (California), Sonora Police Department, Suisun City Police Department, Taft Police Department, Tracy Police Department, Turlock Police Department, Tustin Police Department, Union City Police Department, Walnut Creek Police Department, Whittier Police Department, Yolo County Sheriff's DepartmentAvenal Police Department, Belmont Police Department, Brentwood Police Department, California City Police Department, Chino Police Department, Chowchilla Police Department, Colma Police Department, Crescent City Police Department, Downey Police Department, El Centro Police Department, El Monte Police Department, Fairfield Police Department, Folsom Police Department, Fresno Police Department, Glendora Police Department, Hawthorne Police Department, Inyo County Sheriff's Department, Kern County Sheriff's Department, Los Banos Police Department, Los Gatos/Monte Sereno Police Department, Mountain View Police Department, Newark Police Department, Newport Beach Police Department, Orange County Sheriff's Department, Orange Police Department, Pleasant Hill Police Department, Richmond Police Department, San Bruno Police Department, San Diego County Sheriff's Department, San Fernando Police Department, San Ramon Police Department, Santa Barbara County Sheriff's Office, Santa Barbara Police Department, Santa Clara Police Department, Santa Cruz County Sheriff's Office, Santa Maria Police Department, Seaside Police Department, Signal Hill Police Department, Solano County Sheriff's Office, South Pasadena Police Department, Torrance Police Department, Tracy Police Department
Federal—Drug Enforcement Administration, U.S. Fish and Wildlife Service
IdahoTwin Falls Police Department—
IllinoisQuincy Police Department (Illinois)—
IndianaLebanon Police Department (Indiana)—
KansasTopeka Police Department—
Louisiana—Jefferson Parish Sheriff's Office
MarylandSt. Michaels Police Department—
Massachusetts—Braintree Police Department
Michigan—Grand Rapids Police Department
MissouriBerkeley Police Department (Missouri)—
Nevada—University Police Department, Southern Command (Nevada)
New YorkTompkins County Sheriff's Office—
OregonAshland Police Department (Oregon)—
UtahWeber County Sheriff's Office, West Jordan Police Department—
VirginiaMadison County Sheriff's Office (Virginia)Leesburg Police Department (Virginia)
WashingtonMarysville Police Department (Washington)Jefferson County Sheriff's Office (Washington)
Wisconsin—Oshkosh Police Department

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