Duty Arms IndexWhich police departments use the Colt M4 Carbine?
Data coverage: Based on 59 agencies in the Duty Arms Index with a current, sourced Colt M4 Carbine entry, any role except SWAT/tactical-unit listings (entries the source lists as a Colt M4 Carbine (the shorter M4 Commando is not included)). Shares are of 200 agencies with a sourced primary patrol rifle. 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 agency. Data last updated Oct 10, 2026.
How agencies issue it
Each agency counted once, under its highest role for the Colt M4.
- Primary duty33 (55.9%)
- Other / authorized26 (44.1%)
By agency type
- Local police46
- Sheriff's office9
- Federal3
- Special jurisdiction1
Variants and generations
As named in each agency's source.
- Colt M4 Carbine59 agencies
Agencies that stopped issuing the Colt M4 Carbine (1)
Agencies with a sourced previous Colt M4 entry and no current one, newest change first (year shown where the source dates it), with the patrol rifle they carry now. Most common replacement: SIG Sauer M400 (1).
| Agency | Previously | Carries now |
|---|---|---|
| Virginia State PoliceVA | Colt M4 Carbine | SIG Sauer M400 |
Colt M4 Carbine agencies by state
Every agency with a current, sourced Colt M4 entry, largest first. Each links to its loadout, sources and history.
- California45 agencies
San Diego County Sheriff's Department · Orange County Sheriff's Department · Inyo County Sheriff's Department · Kern County Sheriff's Department · Santa Barbara County Sheriff's Office · Santa Cruz County Sheriff's Office · Solano County Sheriff's Office · Avenal Police Department · Belmont Police Department · Brentwood Police Department · California City Police Department · Chino Police Department · Chowchilla Police Department · Citrus Heights 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 · Los Banos Police Department · Los Gatos/Monte Sereno Police Department · Modesto Police Department · Mountain View Police Department · Newark Police Department · Newport Beach Police Department · Orange Police Department · Pleasant Hill Police Department · Red Bluff Police Department · Richmond Police Department · San Bruno Police Department · San Fernando Police Department · San Ramon Police Department · Santa Barbara Police Department · Santa Clara Police Department · Santa Maria Police Department · Seaside Police Department · Signal Hill Police Department · South Pasadena Police Department · Torrance Police Department · Tracy Police Department
- Federal3 agencies
Drug Enforcement Administration · Bureau of Alcohol, Tobacco, Firearms and Explosives · U.S. Fish and Wildlife Service
- Virginia2 agencies
Falls Church Police Department · Leesburg Police Department (Virginia)
- Arizona1 agency
- Hawaii1 agency
- Louisiana1 agency
- Massachusetts1 agency
- Michigan1 agency
- Nevada1 agency
- North Carolina1 agency
- Washington1 agency
- Wisconsin1 agency
Frequently asked
- Which police departments use the Colt M4 Carbine?
- 59 law enforcement agencies in the Duty Arms Index currently issue the Colt M4 Carbine, including Drug Enforcement Administration, Bureau of Alcohol, Tobacco, Firearms and Explosives, San Diego County Sheriff's Department and Honolulu Police Department. 33 of them carry it as their primary patrol rifle. The list covers entries the source lists as a Colt M4 Carbine (the shorter M4 Commando is not included).
- How common is the Colt M4 Carbine in police service?
- 33 of 200 agencies with a sourced primary patrol rifle (16.5%) issue the Colt M4 Carbine as that primary, making it the #2 patrol rifle family in the index, behind the Colt AR-15.
- Which states have the most agencies using the Colt M4 Carbine?
- California (45), Federal (3), Virginia (2) and Arizona (1). Agencies in 12 states plus federal agencies have a sourced Colt M4 entry. State counts follow where the index has the most sourced agencies, so they are not a census.
- Which agencies stopped using the Colt M4 Carbine?
- 1 agencies list the Colt M4 as previously issued and no longer have a current Colt M4 entry, including Virginia State Police. The most common replacement is the SIG Sauer M400 (1 of them).