Description

The 20F2 is the navalized version of the GIAT CN-MIT 20 M693 (Canon Mitrailleur 20 mm Modèle 693), formerly the Hispano-Suiza 820. This weapon is also used by the French Army.

The M621 is a low-recoil gun which has been mainly used on helicopters and small aircraft, but a navalized version was developed in the late 1980s. Recoil is minimized by the use of a muzzle brake and a shock-absorbing mount.

Gun Characteristics

Designation 20 mm/90 GIAT M693 CN-MIT-20F2
20 mm/73 GIAT M621
Ship Class Used On France: Florèal, Tripartite minelayers, P400, CDIC and EDIC classes
Belgium: Tripartite minelayers
Indonesia: Tripartite minelayers
Malawi: Kasunga
Netherlands: Tripartite minelayers
Pakistan: Tripartite minelayers
Saudi Arabia: NAJA 12 class
Date Of Design Late 1970s
Date In Service 20F2: 1983 (Naval Version)
M621: 1988 (Naval Version)
Gun Weight 20F2: N/A
M621: 104 lbs. (47 kg)
Gun Length oa 20F2: N/A
M621: 87 in (2.207 m)
Bore Length 20F2: about 71 in (1.800 m)
M621: about 57 in (1.460 m)
Rifling Length N/A
Grooves N/A
Lands N/A
Twist N/A
Chamber Volume N/A
Rate Of Fire 20F2: 800 rounds per minute cyclic
M621: 740 rounds per minute cyclic

Ammunition

Type Fixed
Weight of Complete Round
  • 20F2:
    • HE: 0.562 lbs. (0.255 kg)
  • M621: N/A
Projectile Types and Weights
  • 20F2:
    • HE: 0.265 lbs. (0.120 kg)
    • APDS: 0.238 lbs. (0.108 kg)
  • M621: 0.223 lbs. (0.101 kg)
Bursting Charge N/A
Projectile Length N/A
Propellant Charge N/A
Muzzle Velocity
  • 20F2:
    • HE: 3,440 fps (1,050 mps)
    • APDS: 4,100 fps (1,250 mps)
  • M621:
    • HE: 3,215 fps (980 mps)
    • AP: 3,380 fps (1,030 mps)
Working Pressure N/A
Approximate Barrel Life 16,000 rounds
Ammunition stowage per gun
(on mount)		 20F2: 320 rounds in two 160-round magazines
M621: 160 rounds in single magazine

Range

Range of 20F2
Elevation HE AP
Effective 2,200 yards (2,000 m) 1,300 yards (1,200 m)
Maximum 10,960 yards (10,020 m) 7,400 yards (6,770 m)

Mount/Turret Data

Designation 20F2: Affût 15B
M621: Affût 15A
Weight 15B: 688 lbs. (312 kg) without ammunition
15A: 417 lbs. (189 kg) without ammunition
Elevation 15B: -10 / +40 degrees
15A: -10 / +40 degrees
Elevation Rate Manual Elevation, only
Train -170 / +170 degrees
Train Rate Manual Training, only
Gun recoil N/A

These mountings use a collimator gunsight.

Additional Pictures

Sources

Data from:

  • "The Naval Institute Guide to World Naval Weapon Systems 1991/92" and "1994 Update" both by Norman Friedman
  • "Rapid Fire" by Anthony G. Williams

Other:

Page History

21 May 2006
Benchmark
03 March 2012
Updated to latest template