Source: ATF P 5300.11 · Curios or Relics List · Jan 1972 – Apr 20253,573 entries · 4 sections
The C&R RegisterA finding aid to the ATF Curios or Relics List, for Type 03 collectors
C&R · IV · 040

Colt Monitor machine rifle

Section IV: still an NFA firearm, also a curio or relic

Official wording

ATF P 5300.11 · APRIL 2025 EDITION · SECTION IV · VERBATIM · PDF P. 83 ↗

Colt, Monitor Model machine rifle, cal. 30-06, commercial version of the BAR, 18" barrel, vertical pistol grip, Cutts compensator, mfd. by Colt.

What this entry requires

  • ATF REQUIRESMade or imported as stated: “mfd. by Colt”
  • ATF REQUIRESConfigured as the ATF wording states: “18" barrel, vertical pistol grip, Cutts compensator”
  • INFOATF states no date; production was about 1931–1933.
  • INFOStill an NFA firearm; only registered examples transfer, with ATF approval (26 U.S.C. 5812, 5861).

Editorial facts · Our research

Country
United States
Manufacturer
Colt's Patent Fire Arms Mfg. Co.
Type
Machinegun
Action
Select-fire / auto
Caliber
.30-06
Made
1931–1933production; ATF states no date¹
Service
Commercial
Search listings ↗Check a specific gunReport an error ↗

Source

Official wording
ATF P 5300.11, April 2025 edition · Section IV · PDF p. 83 ↗ · ATF original ↗
Entries
1 line
Verbatim check
Checked against the PDF text before every release
Editorial facts
Confidence: Medium · Last revised 18 October 2026 (Evidence pass) · How we rate confidence
References
  1. Wikipedia, “M1918 Browning automatic rifle” ↗, years (estimate: partly supports it): section 'Colt Monitor': 'In 1931, the Colt Arms Co. introduced the Monitor Automatic Machine Rifle (R80)'; the 1933 end is our estimate.
Fact tags
  • ATF the ATF wording states it.
  • REF ¹ an outside reference supports it; the number points to the list of references.
  • ESTIMATE an approximate or indirect reading, for example the production range of the base model.
  • NO CITATION we haven’t attached a reference for this fact; it’s our editorial reading, not ATF’s.
Source checked
20 October 2026: ATF’s page still lists the April 2025 edition
Corrections
None

Historical context

M1918 Browning automatic rifle (base model shown for Colt Monitor machine rifle)
Shown: a military Browning Automatic Rifle, not the Colt Monitor machine rifle.

Image: Wikimedia Commons, “Army Heritage Museum B.A.R..jpg” by United States Army, Public domain. Retrieved October 2026.

Summary: Wikipedia, “M1918 Browning automatic rifle”. Text CC BY-SA 4.0.

FROM WIKIPEDIA

The Browning automatic rifle (BAR) is a family of American automatic rifle used by the United States and numerous other countries during the 20th century. The primary variant of the BAR series was the M1918, chambered for the .30-06 Springfield rifle cartridge and designed by John Browning in 1917 for the American Expeditionary Forces in Europe as a replacement for the French-made Chauchat and M1909 Benét–Mercié machine guns that U.S. forces had previously been issued.