This gun, entirely of Bofors design, has been in service in Poland, Finland, and Norway, and, to a limited extent, in Sweden. A flash hider is screwed to the muzzle of the tube which is of forged alloy steel. The barrel is good for about 1,500 rounds, and may be changed very easily. The gun is fed by two four-round clips.
The automatic breechblock is of the vertical sliding type. A recuperator spring is assembled near the breech end of the tube. The hydrospring recoil system is housed in a cylinder underneath the recuperator spring, and is held in position by a supporting bracket secured to the breech casing.
Fire control equipment includes one elevation telescope, one azimuth telescope, a Le Prieur-Bofors ballistic corrector, sights, data receivers, and a fuze setter.
The elevating and traversing mechanism of this gun is hand-operated; firing is accomplished by a foot trigger on the lower left-hand side of the carriage.
The four-wheeled mount, which is standard for all calibers of antiaircraft gun up to 10.5 cm, is extremely maneuverable over all kinds of roads and terrain. Construction is simple and, with an experienced crew, the gun can be put in or taken out of action in approximately 30 seconds.
SPECIFICATIONS
| Caliber | 4 cm (1.57 ins.) | |
| Weight (travelling position) | 3,800 lbs. | |
| Weight (firing position) | 3,800 lbs. | |
| Length (travelling position) | 23 ft. | |
| Length of tube | 7.8 ft. (60 cals.) | |
| Width (overall) | 5 ft., 10 ins. | |
| Height (travelling position) | 6 ft., 8 ins. | |
| Height (firing posltion) | 3 ft., 9 ins. (mounted flush) | |
| Rate of fire | 120 to 180 r.p.m. | |
| Muzzle velocity (A.P. shell) | 2,780 f.s. | |
| Range (maximum) | ||
| Horizontal | 9,846 yds. | |
| Vertical | 7,330 yds. | |
| Elevation | 90° | |
| Depression | -5° | |
| Traverse | 360° | |
| Ammunition | H.E. shell tracer effect Bofors (u); Incendiary H.E. shell tracer effect |
|
| Wt. of projectile | Magazine clip with 4 rds—4.6 lbs. |
German: p. 129