This "Military Rifle Components Guide" will provide additional information
and photos of the various components used on the Military Rifles
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                                            BUTTSTOCKS                                                       
The following classification system for Buttstocks was developed by M. Eklund.
        The pictures were taken by both M. Richardson and M. Eklund.
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TYPE A - ORIGINAL SOLID BODY
Approx the first 100 Stocks were
brown fiberglass, with the later
ones being painted green


SCREW:
Short A1 screw, solid with no hole


BUTTPLATE:
Solid one piece plastic


SLING MOUNT:
Original version had a bare metal sling
swivel with front & rear movement,
pinned to the stock body.


BODY:
Solid construction


Used on the "Early" Model 601


                                                                                                                                                                                    

TYPE B - IMPROVED SOLID BODY
Brown fiberglass painted green

SCREW:
Short A1 screw, solid with no hole

BUTTPLATE:
Solid one piece plastic

SLING MOUNT:
bare metal sling swivel with
front & rear movement

BODY:
Solid construction

Used on
"Late" Model 601 - Brown Painted Green
"Early" Model 602 - Black
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TYPE C - INTERMEDIATE SOLID BODY
Black plastic

SCREW:
Short A1 screw, solid with no hole

BUTTPLATE:
Solid one piece plastic

SLING MOUNT:
bare metal sling swivel with
front & rear movement

BODY:
Solid construction

Used first on the Model 602 in 1963

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TYPE D - FINAL SOLID BODY
Black plastic

SCREW:
Short A1 screw, solid with no hole

BUTTPLATE:
Solid one piece plastic

SLING MOUNT:
Rubber/Plastic coated metal sling swivel
with front & rear movement

BODY:
Solid construction

Used on the Model 603 and 604
starting in 1964
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TYPE E - HOLLOW BODY / TRAPDOOR
Black plastic

SCREW:
Short A1 screw, with hole

BUTTPLATE:
Solid one piece plastic, with center opening

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

BODY:
Hollow storage compartment

Used with the Model 603 / M16A1
and latter Models starting in 1969
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                                            BUFFER GROUP                                                   

BUFFERS:
ORIGINAL EDGEWATER SPRING GUIDE:
Used in the Colt Model 601, 602 and 603 / XM16E1 until Dec 1966



STANDARD RIFLE BUFFER:
Started use in late 1966, some variations do exist in the buffers



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SPRINGS:



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TUBES:
ORIGINAL TUBE:
No wrench flats,
hole in tube





STANDARD RIFLE TUBE:






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                                         LOWER RECEIVER                                                   

STYLES:
"SLABSIDE":









"PARTIAL FENCE":









"FULL FENCE":









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TAKEDOWN / PIVOT PINS:
601 FRONT PIVOT PIN:




TAKEDOWN & PIVOT PINS
WITH "DIVOTS":




TAKEDOWN & PIVOT PINS:



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SELECTORS:
ORIGINAL WITH "DIVOTS"
Model 601 and 602


MID-PRODUCTION SELECTOR
Model 603 and later


CURRENT



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BOLT CATCH / RELEASE:








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MAGAZINE RELEASE:








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                                         UPPER RECEIVER                                                    

REAR SIGHTS:

No Directional Arrow
Model 601

Recessed Directional Arrow
Model 602

Raised Directional Arrow
Model 603 and Later Models

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EJECTION PORT COVERS:

Original Model
Square External Detent Plate
Model 601and 602

Late Model
Rectangular External Detent Plate
Model 603 and Later
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                                  BOLT GROUP                                                             

CARRIER/KEY:





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FIRING PINS

ORIGINAL HEAVY FLAT HEAD:




MODIFIED LIGHT FLAT HEAD:




CURRENT ROUND HEAD:





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BOLTS:





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                                      CHARGING HANDLES                                                  

ORIGINAL TRIANGULAR SHAPED:








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LATER STYLE:








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                              HANDGUARD SLIPRINGS                                                    

ORIGINAL FLAT / STRAIGHT:
Found on the Model 601-604








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LATER TAPERED:
Not found on any of the Retro Rifles,
but found on some of the "Late" Retro Carbines








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                                BARRELS
(courtesy of M Eklund aka EKIE)                                     

ORIGINAL WINCHESTER BARREL
Used on Colt Model 601

TWIST RATE: 1/14, Broach Cut 6 Groove

MARKINGS:  Marked with a single M, and at least one W. Some barrels have the old C in Square proof marking
stamped near the breach. As with other early 1960's Colt barrels some have a sideways S stamp also.












The example above is stamped with two W's, one under the FSB, the other just behind the handguard cap. The M
is stamped on the exposed part of the barrel between the legs of the FSB on the right side. There is also a
witness mark at TDC, and the gas port hole is counter bored
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ORIGINAL COLT BARREL
Used on Colt Model 602

TWIST RATE: 1/12

MARKINGS: Colt’s first batch of in house barrels were proof tested and stamped with Colt's proof stamp a V and
a P in a triangle (Verified Proof), the barrel extension was marked with a C, used from 63-66.















A "12" marking was added just over and inch from the muzzle to differentiate the 1/12 barrels from the 1/14
barrels. Marking was used from 1963-1967.












In 1964 Colt’s began marking a M next to the VP marking meaning the barrel had been magnetic particle tested
after proof firing to find potential flaws in the barrel.
















By 1966 barrels were proof marked in the same spot as before, but the proof symbol was changed to a P, so they
now simply read MP, with the M & P run together. This MP marking was moved by 1969.















Starting in October 1967 and prior to serial number 800,000 Colt’s added chrome to the chamber. Chrome
chamber barrels are identified by a C about an inch back from the muzzle rather then the earlier 12. Also note
that along with the "C" mark most of these rifles also had the new bird cage flash suppressor.











By 1969 and before serial number 1,750,XXX Colt's chrome chamber barrels were marked C MP C, and the proof
markings and C were moved to the same spot. This marking was used as late as 1970 or 1971 and serial number
4,552,XXX. The C means Colt’s, the M means Magnetic particle inspected, the P for Proof fired, and the C near
the muzzle for Chrome chamber.











Effective in 1970 or 71 at about serial number 4,700,000 along with the chamber the bores were chromed, early
ones were marked C MP B. The C means Colt’s, the M means Magnetic particle inspected, the P for Proof fired,
and the B for chrome Bore.











Starting in 1974 and after serial number 4,900,000 chrome bores were marked C MP CHROME BORE. This marking
was used until the end of M16A1 production.










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                                            HANDGUARDS                                                       












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                                   FRONT SIGHT BASES                                                     

Original Armalite Cast FSB
Used on the early models to include:
Model 601, 602, 603/XM16E1



Early Forged FSB
Used on:
Model 603 and 604

The first version of the forged front sight base was
machined smooth to remove forging flash

Production started as early as 1964, and was used
as late as 1969 and serial number 1,750,XXX

Early Ones lack the drain hole for the front sight



Late Forged FSB
Used on:
Model 603

Marked with a raised C and a Bell

The C and a Bell was in use by 1970,
and serial number 4,500,000




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                                            FLASHHIDERS                                                        

ORIGINAL 3 PRONG "DUCKBILL":
Used on the Colt Model 601. The lightweight prongs
were prone to bending which led to the creation of
the improved 3 Prong Flashhider.


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IMPROVED 3 PRONG:
Used on the Colt Model 602 and 603 / XM16E1.
The prongs were strengthened to prevent bending,
but the open design was prone to snagging on things
in the field which lead to the improved Birdcage Flashhider.


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A1 BIRDCAGE:
Used on the Colt Model 603 / M16A1 and later Models.





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RETRO BLACK RIFLE - RIFLE GUIDE - COMPONENT GUIDE
ORIGINAL
IMPROVED
An early version of the
Sling Swivel was designed
to rotate 360 degrees.

This Sling Swivel is not
pinned in the center, and
is not interchangeable
with the other sling swivels
S. Siebler
S. Siebler
S. Siebler
Late / Current
Mid
Early
Late / Current
Mid
Early
Early & Late / Current
Early with Divot
Colt Model 601 / 602
601  /  Early  /  Late
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 603
M16A1
Colt Model 604 /   
USAF M16