Nomenclature

warhead

Complette round length (in.)

Complette round weight (lbs)

Color coding

M267

Hydra smoke practice

blue with white markings/brown band

M261

Hydra HE

OD with yellow markings

WDU-4A/A
M255A1

Flechette

54.6

20.2

OD with white markings and diamonds

M257

Illumination

M278

IR Illumination

M229

HE Long

62.8

27.9

OD with yellow markings

M151

HE

54.7

20.8

OD with yellow markings

M274

practice smoke charge

52.8

20.8

blue with white markings

M156

White Phosphorus

52.2

20.6

light green/yellow band/red markings

WTU-1/B

practice solid

52.8

20.8

blue with white markings

M264

White smoke

CHARACTERISTIC

MK 66

MK 40

Length without warhead

41.7 inches

39.3 inches

Motor burn time (77F)

1.05 - 1.1 sec.

1.55 - 1.69 sec.

Average thrust

1,300-1370 lbs.

720 lbs.

Average spin rate

9 - 10 rps

1 rps

Motor burn out

1280 feet (397 m)

1460 feet (445 m)

Velocity at motor burnout

2425 fps

1965 fps

Maximum range

10,425 meters

8,080 meters

spin-stabilized

fin-stabilized