Atmed

NAME – Atmed

COUNTRY OF ORIGIN – USA

DATE OF MANUFACTURE – 1940

CALIBER – 11.43x23mm (.45 ACP)

OVERALL LENGTH – 85.3 cm (33.6 in)

BARREL LENGTH – 29.2 cm (11.5 in)

RIFLING (TYPE & TWIST) – 7 Groove, Right hand twist

BULLET DIAMETER – 11.46 mm (0.451 in)

BULLET WEIGHT – 15 g (230 grain)

MUZZLE VELOCITY – 290 m/s (950 fps)

MUZZLE ENERGY – 625 j (451 ft/lbs)

WEIGHT (EMPTY) – 4.30 kg (9lbs 7.7 oz)

WEIGHT (LOADED) – 5.18 kg (11 lbs 6.8 oz)

SIGHTS – Front – blade

EFFECTIVE RANGE – 183 meters (200 yds)

OPERATION – Advanced primer ignition, blowback

TYPE OF FIRE – Selective, Semi and Full automatic

RATE OF FIRE – 40 rpm (Semi), 75 rpm (Full)

CYCLIC ROF – 524 rpm

FEED DEVICE – 30 round box magazine, double column, double feed.

FEED DEVICE WEIGHT (EMPTY) – 0.25 kg (8.8 oz)

FEED DEVICE WEIGHT (LOADED) – 0.88 kg (1 lb 15.2 oz)

BASIC LOAD – 4 – 30 round magazines (120 rounds)

LOAD WT – 3.52 kg (7 lbs 12.2 oz)

MANUFACTURER – Atmed Manufacturing Co.

STATUS – Obsolete

SERVICE – Tested only, no US service or commercial sales

     This was another George J. Hyde design submitted for US submachinegun trials early in World War II. The Atmed was basically an improved version of the Hyde model 1935. It was tested at Aberdeen Proving Grounds on 3-7 September 1940. It was considered the best submachinegun of the 1942 US trials. The Atmed was easy to handle and accurate. But the advanced primer ignition system used was sensitive to primers and did not function well with issue ammunition. Commercial ammunition functioned reasonably well in the Atmed and misfiring was eliminated with a slight (0.009 in) shortening of the firing pin. But the difficulties in functioning the Atmed far outweighed any handling characteristics and the weapon was eliminated from any further development.