Please click here to visit the "Military Rifle Components Guide" for
additional info and photos of the various components used on this model.
HISTORY / BACKGROUND:-
The Colt Model 603 / M16A1 was the final model that incorporated all of the improvements requested by the
US Military. Those Improvements included, a modified buttstock with internal storage space, etc.



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BUTTSTOCK:
SCREW:
Short A1 screw, with hole

BUTTPLATE:
Solid one piece plastic

SLING MOUNT:
Fixed metal sling mount, attached
to the stock body with a screw

BODY:
Hollow storage compartment



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BUFFER GROUP:
BUFFER:
Improved / current  rifle buffer


SPRING:



TUBE:
Current tube with wrench flats on end

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LOWER RECEIVER:
STYLE:
Full Fence


MARKINGS:
Colt Logo
PROPERTY
OF U.S. GOVT.
XM 16 E1
CAL. 5.56 M.M.
Serial XXXXXXX


SELECTOR:
"Later"


TAKEDOWN / PIVOT PINS:
"Later" Pins


BOLT CATCH/RELEASE:
"Latter" with Raised/Grooved End

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UPPER RECEIVER:
PROOF MARKS / FORGE CODE:
Colt Proof Marks - Triangle & Square with "C"
Located in front of ejection port
No Forge Code


REAR SIGHT:
Raised Directional Markings on Receiver


EJECTION PORT COVER:
"Later" with " Rectangular Plate"
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BOLT GROUP:
CARRIER:
Manganese Phosphate Finish with Forward Assist Serrations

BOLT:
Manganese Phosphate Finish

FIRING PIN:
Improved Light Flat Head



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CHARGING HANDLE:
Improved / Current  Design







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HANDGUARD SLIP RING:
Flat





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BARREL:
DIAMETER:
0.625" at the Front Sight Base

LENGTH:
20"

TWIST RATE:
1/12

MARKINGS:
See the Rifle Guide for Details

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HANDGUARDS:
Standard Black Triangular

Early - with drain holes

Late - with drain holes and "left" & "right" markings
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FRONT SIGHT BASE:
STYLE:
Early - Forged, with flash removed

Late - Forged


MARKINGS:
Early - No Markings

Late - "Bell" & "C"



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FLASHHIDER:
A1 Birdcage
RETRO BLACK RIFLE - RIFLE GUIDE - MODEL 603 / M16A1
Unknown Date - Vietnam
US Army
Unknown Date - Vietnam
US Army

ADDITIONAL COLT MODEL 603 / M16A1 INFORMATION
setstats
.223 Cal / 5.56mm
MILITARY RIFLE
GUIDE
Military Rifle
Components Guide
Colt Model 601
Colt Model 602
Colt Model 603 /
XM16E1
Other M16A1
Manufacturers
Colt Model 604 /   
USAF M16
Colt Model 603
M16A1
Colt Model 606
HBAR