Here's the EXACT text from the
HANDBOOK OF ORDINACE MATERIEL
ST 9-159
US ARMY ORINANCE CENTER AND SCHOOL
ABERDEEN PROVING GROUNDS
MARYLAND
SUBMACHINEGUN, CAL .45, THOMPSON, M1 AND M1A1
1005-672-1754 (M1)
1005-672-1755 (M1A1)
CLASSIFICATION.............LIMITED STANDARD
WEIGHT, WO/EQUIPMENT.......10 LB 7 OZ
LENGTH:
OVERALL..................31-3/8 IN
BARREL...................10-1/2 IN
OPERATION..................BLOWBACK
FEED.......................MAGAZINE (20 OR 30RD)
COOLING....................AIR
AMMUNITION TYPE............BALL, TRACER, AND DUMMY
MUZZLE VELOCITY (BALL
234 GRAIN BULLET)........920 FPS
MAXIMUM RANGE (BALL
30º ELEVATION)...........1,960 YD
RATE OF FIRE...............700 TO 800 RD/MIN
DIFFERENCES AMONG MODELS:
M1A1 DIFFERS FROM M1 ONLY IN HAVING A
FIXED FIRING PIN IN PLACE OF MOVABLE
FIRING PIN AND HAMMER.
SNL A-32
TM 9-215
SUBMACHINEGUN, CAL .45, THOMPSON, M1928A1
1005-672-1740
CLASSIFICATION.............LIMITED STANDARD
WEIGHT, WO/EQUIPMENT.......10 LB 9 OZ
LENGTH:
OVERALL..................33-7/8 IN
BARREL...................10-1/2 IN
OPERATION..................DELAYED BLOWBACK
FEED.......................MAGAZINE (20 RD)
COOLING....................AIR
AMMUNITION TYPE............BALL, TRACER, AND DUMMY
MUZZLE VELOCITY (BALL
234 GRAIN BULLET)........920 FPS
MAXIMUM RANGE (BALL
30º ELEVATION)...........1,960 YD
RATE OF FIRE...............600 TO 700 RD/MIN
DIFFERENCES AMONG MODELS:
TM 9-1215
and by the way, the pictures in the book show that only the M1928A1 had the cutts compenstaor.
Hah!
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"Victory at any Price!"
SS-Panzergrenadier