Back to working on my Colt retro build....

deadman

CGN Ultra frequent flyer
Rating - 100%
169   0   0
A couple years ago I decided I wanted to try messing around with an AR. I didn't know anything about them then, still don't. Anyway, this is what I've got. It mostly sat in the safe after I put it together and I called it good enough but winter's here now and I need a project so I'd like to pick away at it and make it more "correct". It's on a Colt A2 (GS serialed) receiver so I know that's not correct but its what I've got.

The barrel is 10.5", unmarked as far as I can tell so I don't know what its from. The upper is marked C M, and the fh is 5.5" so I don't know if its correct for anything. I guess at this point its kind of an attempt at a 610? because of the lack of a forward assist.

I've got an A2 grip I removed the finger groove from because I had it, and an old aluminum stock a forum member gave me a while back. What I'm looking for is a little insight about what needs to be changed, and what I should be aiming for in regards to making it as close to an original as possible. And, am I on the right track or is this simply a poor mashup of various parts that aren't representative of an actual firearm?

Here are some pics:

tFOLu9n.jpg


VxhO21U.jpg


CKyUXt5.jpg


j8DuN90.jpg


qXeoj8l.jpg


yUh7Hpt.jpg


thi6F65.jpg
 
Looks awesome :)

You need to change that M4 buffer tube nut for a old style one and find a 2 position buffer tube.

lockringHT1.jpg


Also a M16A1 grip.

69f162_ff55f754cb4b4371835672cf4d5a1c26~mv2.jpg_srz_273_262_85_22_0.50_1.20_0.00_jpg_srz
 
I would say it's a pretty good basis for a Commando XM177 or GAU-5/A, which are the same thing. One thing to be aware of is that regardless of how it's marked that lower receiver is definitely not an A2 (4th pattern). From 1964-85 Colt built all of their commercial semi-auto receivers (SP1, SP2 and early AR-15A2 sporters) on lowers forged with the old dies used to make the lowers for the 601 and 602 (1st pattern). These lowers had no reinforcements around the lower receiver extension hole, a relatively small radius at the pivot pin lugs, no magazine release fence and no pivot pin retaining boss. The US military mandated the captive pivot pin when the M16 was type classifed in 1964, so the 1st pattern receivers could not be sold to the DoD, and Colt diverted them to civilian offerings. Thus your receiver style is actually an older design than the Commando series, which I believe all featured 2nd pattern lowers (distinguished by the addition of the pivot pin retaining boss but no magazine release fence).

This photo shows an XM177E1, essentially the same gun but with a forward assist, built on a 2nd pattern lower.
post-1885-1234329927.jpg
 
Someone might like that slab lower for a M16 601/602 build

I'm collecting some parts now, that's the next one I'm planning. I'm sure I'll have more questions when that one starts!

I would say it's a pretty good basis for a Commando XM177 or GAU-5/A, which are the same thing. One thing to be aware of is that regardless of how it's marked that lower receiver is definitely not an A2 (4th pattern). From 1964-85 Colt built all of their commercial semi-auto receivers (SP1, SP2 and early AR-15A2 sporters) on lowers forged with the old dies used to make the lowers for the 601 and 602 (1st pattern). These lowers had no reinforcements around the lower receiver extension hole, a relatively small radius at the pivot pin lugs, no magazine release fence and no pivot pin retaining boss. The US military mandated the captive pivot pin when the M16 was type classifed in 1964, so the 1st pattern receivers could not be sold to the DoD, and Colt diverted them to civilian offerings. Thus your receiver style is actually an older design than the Commando series, which I believe all featured 2nd pattern lowers (distinguished by the addition of the pivot pin retaining boss but no magazine release fence).

This photo shows an XM177E1, essentially the same gun but with a forward assist, built on a 2nd pattern lower.
post-1885-1234329927.jpg

Ah ok, I was going by the "A2" markings on the receiver but thanks for the clarification. There are a lot of little details I need to learn about I suppose (such as the early style buffer tube nut Dsiwy mentioned and the differences in receivers as you pointed out).

More parts hunting....
 
Get an old style colt 3x scope. They were the first optic / gun combination, before the m4/scope

note that the us military used a custom screw to affix the scope to the m16a1. Got this with my xm16e1
used in Vietnam
 
Last edited:
Is there a commercially available lower with only a partial fence other than the Nodak retro stuff? Did Colt ever put them on rifles available to the public or do I have to modify a full fence unit to get "the look"? And if that's my only option, is there anyone around Canada that would be able to refinish it to resemble the original finish?
 
"Is there a commercially available lower with only a partial fence other than the Nodak retro stuff?"

No.

Did Colt ever put them on rifles available to the public or do I have to modify a full fence unit to get "the look"?

No, they didn't. If you don't want a Nodak you will have to modify something, but Nodak is finally going to start selling to Canadians so why wouldn't you go that way?
 
Nodak AFAIK are the only company to ever offer partial fence lowers commercially.

It's looking pretty good. How many holes in the handguards? Colts had six, most commercial have seven.

Nice score on the buttstock, shame about the sling loop.

I have a 601 style front pivot pin that someone made to replace the Colt two piece screw.

Get yourself some 5/20 rd mags.
 
That's great that you can get it fixed. FYI the very first XM 177 didn't have the vinyl acetate covering on the stock. They were anodized grey just like the upper and lower. I dig the been there done that look too though.
 
Back
Top Bottom