AR15/M16 A1 Upper: Model Guide/Build Guide/FAQ
AR15/M16 A1 Upper Model Guide
There were basically 7 different styles of the retro upper. They included the Trigger charging handle, 4
"slick-side" versions, and 2 versions of forward assists"
Trigger Charging Handle Upper:
The "Trigger Charging Handle" was original upper design and was only found on the first 17 prototypes.
The sight markings are absent .
A reproduction from NoDak Spud is below:
The "correct" lower to use for a Prototype reproduction would be a "slabside" lower pictured below.
_________________________________________________________________________________________________
Colt Model 601 Upper:
The 601 upper was the second upper design.
It accommodates a triangle or standard charging handle.
It also has no provisions for a forward assist.
The rear sight markings are absent.
The correct lower to use for a 601 reproduction would be a "slabside" lower
.
_________________________________________________________________________________________________
Colt Model 602 Upper:
The 602 upper was the third upper design.
It also has no provisions for a forward assist.
The rear sight markings are stamped.(engraved)
The correct lower to use for a 602 reproduction would be a "slabside" lower.
_________________________________________________________________________________________________
Colt Model 604 Upper:
The 604 style upper was the fourth upper design.
It also has not provisions for a forward assist.
The rear sight markings are raised.
Very Early 604 Upper: (Square Forging and matches magazine hump on lower)
Early 604 Upper: (Square Forging, but no longer matches magazine hump on lower)
Later 604 Upper (Rounded Forging)
The 604 style upper was used for the following Colt Models: 604, 605, 607, 608, 610, 630, 639, 649, 652, and 654
Colt 604 utilizes a partial fence lower(early) or full fence lower(late)
Colt 605 utilizes a partial fence lower
Colt 607 utilizes a partial fence lower
Colt 608 utilizes a partial fence lower
Colt 610 utilizes a partial fence lower (Early) or a full fence lower (Late)
Colt 630 utilizes a full fence lower
Colt 639 utilizes a full fence lower
Colt 649 utilizes a full fence lower
Colt 652 utilizes a full fence lower
Colt 654 utilizes a full fence lower
Colt 605 Upper:
The 605 upper started out as a forward assist forging but instead of having the forward assist hole reamed, it
was milled off leaving a unique hump.
Note: some 605s were made with plain 604 uppers.
The rear site markings are raised.
Colt 605 utilizes the partial fence lower
______________________________________________________________________
Forward Assist Uppers:
Colt forward assist uppers come inthree basic types.
Two types without a deflector (also called a Brunton Bump) those without forge codes and those with.
The third type has a deflector and forge codes.
There are also forward assist uppers that were build by H&R and GM. (These are not covered in the Upper
Build Guide)
Colt Early 603 Upper:
The early Colt 603 upper had no forge codes under the rear site.
The upper has provisions for a forward assist .
The rear site markings are raised.
The early Colt 603 upper was used for the following Colt models: 603 XM16E1, 609, 619, and 629.
Colt 603 XM16E1 utilizes a partial fence lower
Colt 609 utilizes a partial fence lower (early) or full fence lower (late)
Colt 619 utilizes a full fence lower
Colt 629 utilizes a full fence lower
_________________________________________________________________________________________________
Colt Late 603 Upper:
The late Colt 603 upper had forge codes under the rear site.
The upper has a provision for a forward assist.
The rear site markings are raised.
The Late Colt 603 upper was used to the following Colt models: 603 M16A1, 639, 651, and 653
Colt 603 M16A1 utilizes a full fence lower
Colt 639 utilizes a full fence lower
Colt 651 utilizes a full fence lower
Colt 653 utilizes a full fence lower
_________________________________________________________________________________________________
Colt/Diemaco C7 upper:
The Colt or Diemaco upper can be found with Colt, or Diemaco stylized 'D' forge codes or both.
They can be identified by the case deflector (Brunton Bump) similar to A2 uppers.
The C7 upper is used for the following models: Canadian/Diemaco C7, C8, and some exported models.
Canadian/Diemaco C7 utilize the C7 upper
Canadian C8 utilizes the C7 upper
_______________________________________________________________________________________________________________
Gas Tubes:
Below are examples of early and late gas tubes:
Early Gas Tube
Late Gas Tube
_________________________________________________________________________________________________
FAQ
1. Does anyone currently manufacturer retro uppers?
YES. -
Below is a current list of Manufacturers/Dealers:
Prototype Trigger Charging Handle: NoDak
603: NoDak
604: Fulton Armory, NoDak
605: NoDak
C7: Fulton Armory. Bushmaster, DPMS, MidwayUSA, and possibly more
2. Where am I supposed to find gray colored parts?
A. Check GunBroker or the AR15.com EE section.
B. Jerrell Sharp (Heatnbeat) makes some very convincing reproductions. Contact him at JRS @ outdrs.net
Above is not a live link, copy it to your address line, then remove the spaces beside the "@"
C. You can send them to someone to be parkerized, or do it yourself.
D. Paint with either Duracoat or Norrels.
3. Is it possible to purchase a "used" A1 uppers?
YES - There are a number of commercial semi-auto and military full-auto uppers that can be purchased. Some
of these can obviously be a challenge to find and they can also demand a pretty high price.
4. What if I want to build a 601 or 602 and I can't afford an original upper?
You can purchase a 604 upper from NoDak or Fulton Armory, mill or sand off the sight markings and have it
re-anodized for a 601.
For a 602 you will need to have the sight marking engraved and then have the upper re-anodized.
In 2009 prices you're looking at between $210-$300 to make a reproduction 602 upper.
5. Can you mix & match the "milspec" A1 small-hole lowers and uppers with the civilian
SP1 large hole lowers and uppers?
YES - there are a number of companies that make adapter pins/screws that will allow you to use a small hole
lower on a large hole upper and vise-versa.
6. Is there a gunsmith who will do the 601/602 modification?
Basically, NO - There are individuals who have done these modifications, but currently no one has offered to
do this on a large scale public basis.
AR15/M16 A1 Upper Model Guide
There were basically 7 different styles of the retro upper. They included the Trigger charging handle, 4
"slick-side" versions, and 2 versions of forward assists"
Trigger Charging Handle Upper:
The "Trigger Charging Handle" was original upper design and was only found on the first 17 prototypes.
The sight markings are absent .
A reproduction from NoDak Spud is below:
The "correct" lower to use for a Prototype reproduction would be a "slabside" lower pictured below.
_________________________________________________________________________________________________
Colt Model 601 Upper:
The 601 upper was the second upper design.
It accommodates a triangle or standard charging handle.
It also has no provisions for a forward assist.
The rear sight markings are absent.
The correct lower to use for a 601 reproduction would be a "slabside" lower
.
_________________________________________________________________________________________________
Colt Model 602 Upper:
The 602 upper was the third upper design.
It also has no provisions for a forward assist.
The rear sight markings are stamped.(engraved)
The correct lower to use for a 602 reproduction would be a "slabside" lower.
_________________________________________________________________________________________________
Colt Model 604 Upper:
The 604 style upper was the fourth upper design.
It also has not provisions for a forward assist.
The rear sight markings are raised.
Very Early 604 Upper: (Square Forging and matches magazine hump on lower)
Early 604 Upper: (Square Forging, but no longer matches magazine hump on lower)
Later 604 Upper (Rounded Forging)
The 604 style upper was used for the following Colt Models: 604, 605, 607, 608, 610, 630, 639, 649, 652, and 654
Colt 604 utilizes a partial fence lower(early) or full fence lower(late)
Colt 605 utilizes a partial fence lower
Colt 607 utilizes a partial fence lower
Colt 608 utilizes a partial fence lower
Colt 610 utilizes a partial fence lower (Early) or a full fence lower (Late)
Colt 630 utilizes a full fence lower
Colt 639 utilizes a full fence lower
Colt 649 utilizes a full fence lower
Colt 652 utilizes a full fence lower
Colt 654 utilizes a full fence lower
Colt 605 Upper:
The 605 upper started out as a forward assist forging but instead of having the forward assist hole reamed, it
was milled off leaving a unique hump.
Note: some 605s were made with plain 604 uppers.
The rear site markings are raised.
Colt 605 utilizes the partial fence lower
______________________________________________________________________
Forward Assist Uppers:
Colt forward assist uppers come inthree basic types.
Two types without a deflector (also called a Brunton Bump) those without forge codes and those with.
The third type has a deflector and forge codes.
There are also forward assist uppers that were build by H&R and GM. (These are not covered in the Upper
Build Guide)
Colt Early 603 Upper:
The early Colt 603 upper had no forge codes under the rear site.
The upper has provisions for a forward assist .
The rear site markings are raised.
The early Colt 603 upper was used for the following Colt models: 603 XM16E1, 609, 619, and 629.
Colt 603 XM16E1 utilizes a partial fence lower
Colt 609 utilizes a partial fence lower (early) or full fence lower (late)
Colt 619 utilizes a full fence lower
Colt 629 utilizes a full fence lower
_________________________________________________________________________________________________
Colt Late 603 Upper:
The late Colt 603 upper had forge codes under the rear site.
The upper has a provision for a forward assist.
The rear site markings are raised.
The Late Colt 603 upper was used to the following Colt models: 603 M16A1, 639, 651, and 653
Colt 603 M16A1 utilizes a full fence lower
Colt 639 utilizes a full fence lower
Colt 651 utilizes a full fence lower
Colt 653 utilizes a full fence lower
_________________________________________________________________________________________________
Colt/Diemaco C7 upper:
The Colt or Diemaco upper can be found with Colt, or Diemaco stylized 'D' forge codes or both.
They can be identified by the case deflector (Brunton Bump) similar to A2 uppers.
The C7 upper is used for the following models: Canadian/Diemaco C7, C8, and some exported models.
Canadian/Diemaco C7 utilize the C7 upper
Canadian C8 utilizes the C7 upper
_______________________________________________________________________________________________________________
Gas Tubes:
Below are examples of early and late gas tubes:
Early Gas Tube
Late Gas Tube
_________________________________________________________________________________________________
FAQ
1. Does anyone currently manufacturer retro uppers?
YES. -
Below is a current list of Manufacturers/Dealers:
Prototype Trigger Charging Handle: NoDak
603: NoDak
604: Fulton Armory, NoDak
605: NoDak
C7: Fulton Armory. Bushmaster, DPMS, MidwayUSA, and possibly more
2. Where am I supposed to find gray colored parts?
A. Check GunBroker or the AR15.com EE section.
B. Jerrell Sharp (Heatnbeat) makes some very convincing reproductions. Contact him at JRS @ outdrs.net
Above is not a live link, copy it to your address line, then remove the spaces beside the "@"
C. You can send them to someone to be parkerized, or do it yourself.
D. Paint with either Duracoat or Norrels.
3. Is it possible to purchase a "used" A1 uppers?
YES - There are a number of commercial semi-auto and military full-auto uppers that can be purchased. Some
of these can obviously be a challenge to find and they can also demand a pretty high price.
4. What if I want to build a 601 or 602 and I can't afford an original upper?
You can purchase a 604 upper from NoDak or Fulton Armory, mill or sand off the sight markings and have it
re-anodized for a 601.
For a 602 you will need to have the sight marking engraved and then have the upper re-anodized.
In 2009 prices you're looking at between $210-$300 to make a reproduction 602 upper.
5. Can you mix & match the "milspec" A1 small-hole lowers and uppers with the civilian
SP1 large hole lowers and uppers?
YES - there are a number of companies that make adapter pins/screws that will allow you to use a small hole
lower on a large hole upper and vise-versa.
6. Is there a gunsmith who will do the 601/602 modification?
Basically, NO - There are individuals who have done these modifications, but currently no one has offered to
do this on a large scale public basis.
RETRO BLACK RIFLE - RETRO UPPER BUILD GUIDE
 | |  | |  | |  | |  | |  | |  |
Partial Fence Lower
Full Fence Lower
Slabside Lower
Slabside Lower
Slabside Lower
Partial Fence Lower
Full Fence Lower
Partial Fence Lower
Full Fence Lower
| "RETRO" BUILD GUIDE |
| .223 Cal / 5.56mm |
