NAME – Colt Model 633HB
COMMON NAMES – Colt 9mm Submachinegun, DOE Colt, Colt Briefcase SMG
COUNTRY OF ORIGIN – USA
DATE OF MANUFACTURE – 1988
CALIBER – 9x19mm NATO
OVERALL LENGTH – 53.3 cm (21 in) Stock collapsed, 61.6 cm (24.25 in) Stock extended
BARREL LENGTH – 17.8 cm (7 in)
RIFLING (TYPE & TWIST) – Six groove, Right hand twist, 1 turn in 25.4 cm (10 in)
BULLET DIAMETER – 9.02 mm (.355 in)
BULLET WEIGHT – 7.45 g (115 gr)
MUZZLE VELOCITY – 365 m/s (1200 fps)
MUZZLE ENERGY – 496 j (366 ft/lbs)
WEIGHT (EMPTY) – 2.45 kg (5 lbs 6.5 oz)
WEIGHT (LOADED) – 3.049 kg (6 lb 11.6 oz) with 32 round magazine
SIGHTS – Front, Post, adjustable for elevation, Rear – flip-type apertures, adjustable for windage, short range 0-50 m (0 -55 yds), and long range 50-100 m (55 – 109 yds)
EFFECTIVE RANGE – 100 m (109 yds)
OPERATION – Blowback, fires from closed bolt
TYPE OF FIRE – Selective, Semi and Full automatic
RATE OF FIRE – 50 rpm Semi, 128 rpm Full
CYCLIC ROF – 700-900 rpm
FEED DEVICE – 20 or 32 round box magazine, double column, double feed
FEED DEVICE WEIGHT (EMPTY) – 20 round – 0.191 kg (6.75 oz), 32 round – 0.227 kg (8 oz)
FEED DEVICE WEIGHT (LOADED) – 20 round – 0.417 kg (14.7 oz), 32 round – 0.599 kg (1 lb 5.1 oz)
BASIC LOAD – 6 – 32 round magazines (192 rounds)
LOAD WT – 3.594 kg (7 lbs 14.6 oz)
MANUFACTURER – Colt’s Manufacturing Company, Hartford, Connecticut
STATUS – Out of production
SERVICE – Department of Energy (DOE), other security services
The smallest version of the Colt 9mm submachinegun family was made to fulfill a Department of Energy request for a compact weapon for use around Nuclear Facilities. All of the aspects of the Colt 9mm submachineguns were retained in the Model 633HB with the addition of a short barrel. In spite of the barrel being shorter than the earlier Colt 9mm weapons, it is still the same basic length as most of the world’s 9mm submachineguns. The hand guard was redesigned so as to protect the operator’s hand from slipping forward when firing. The front sight base also acts as a front hand stop besides supporting the collapsible front sight. Addition of the hydraulic buffer helps keep the cyclic rate of fire of the compact weapon down to more manageable levels.
Relatively few of the Model 633HB weapons were made, but it quickly developed a bit of a legend around its compact design. It a has been used by a number of security services as well as the Drug Enforcement Agency. The draw of the weapon is the very compact size and volume of fire is offers to the user. This size has resulted in the nickname “Briefcase Gun” being given to the weapon by some of its users.
Model 633 with a mechanical buffer has a cyclic rate of fire of 800 to 1100 rpm.
