What can you tell me about this Colt AR15 I'm buying?

[Boboclown]

The odd thing is the receiver has the extended feed ramps. Did they do that for non-M4 barrels too?

I'd like to think they started putting the M4 feed ramps in their carbines in the 90s, but I could be wrong and they iust always did that.

 

[Diamondback]

Hey, @Joe Link , maybe a little offtopic, but speaking of Retro Builds, would it be possible to add a subforum for Retro, Clone and Replica Builds? Thinking something dedicated to pooling our "tribal knowledge" to build yesterday's weapons with today's parts, or military facsimiles with civilian-available gear...

 

[Diamondback]

@Joe Link Would building a 6550 mean having to have a factory 6550 upper, or could you just track down correct Colt parts and assemble it yourself?

 

[Joe Link]

Hey, @Joe Link , maybe a little offtopic, but speaking of Retro Builds, would it be possible to add a subforum for Retro, Clone and Replica Builds? Thinking something dedicated to pooling our "tribal knowledge" to build yesterday's weapons with today's parts, or military facsimiles with civilian-available gear...

I'll add that to the list of considerations. I'm not sure if it'd get enough traffic to warrant it's own section, but we could at least add a prefix to the rifle section

@Joe Link Would building a 6550 mean having to have a factory 6550 upper, or could you just track down correct Colt parts and assemble it yourself?

I'm sure this is a personal preference, but to me it wouldn't be a 6550 unless Colt built/assembled the upper.

 

[Joe Link]

One of the guys on ARF shed some light on this. Not sure if he's correct, but it seems to fit.

Your Lower is from a Colt R6550. If it came with the .22 kit it would be a R6550K. Original configuration would be A2 rifle length buttstock, large pivot pin A2 upper receiver with 20" Govt. profile 1/7" twist barrel.
Correct barrel markings should read
C MP 5.56 NATO 1/7

The current upper on the rifle appears to be from some of the conversion kits Colt sold in the 1995-2000 time frame. A2 upper with 16" 1/7 twist M4 barrel was the
AR6620DC Upper Receiver Conversion Kit.
I think A2 upper with 16" 1/9 twist M4 barrel was
AR6622DC.
Flat top upper with 16" 1/7 twist M4 barrel was
AR6920DC
Flat top upper with 16" 1/9 twist M4 barrel was
AR6922DC
I wish I still had some of those old Shotgun News copies laying around. Hoplite ran an add every issue with all those upper conversion kits listed by model no.
Hope this helps

 

[Joe Link]

 

[Core]

A guy I know is in a tight spot, and I've tentatively agreed to buy his Colt AR15 to help him out. It's a fair enough deal that it doesn't really matter what it is as long as it is in fact a Colt AR15, but now I'm curious! I don't know much about it or these older Colt's. The owner bought this new in either 1973 or 1977, he says it has a few hundred rounds through it at most. One thing I found concerning in the photos is the mismatched photos on the upper and lower. Did they come like this from the factory? How do I know it is in fact a Colt upper? Any other info would be appreciated

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This is a commercial 727 or 729 carbine with the slabside lower. Great find. Handguard should have six holes. The castle nut on the extension may have been replaced. Most original 727s had the gen I lock ring and came with the N1 Fiberlite gen I M4 stock. Ask for original furniture if available, if not still a keeper...

 

[Core]

Good question! I won't know until I call Colt. Serial is GS009xxx.

You can lookup the serial online at Colts website, free and instantly.

 

[Core]

I'd like to think they started putting the M4 feed ramps in their carbines in the 90s, but I could be wrong and they iust always did that.

They didn't initially do the M4 feedramps. Colts commercial products are rife with a hodge podge of parts from transition periods. The military would get the revised models per the contracts and civilian models got whater was left or available. Don't assume it's not original. The slabside lowers were used in commercial products long after the military switched to A2 lowers. The 1/9 M4 barrel is different.. All I can think of is that it may have been produced prior to the adoption of the XM4 1/7" It may be pre M4, and post M16A1 commercial. They sold many slabside with A2 uppers commercially. The 1/9 could have been preproduction XM4 barrels. The originals didn't have M4 ramps in the uppers until later.

 

[Joe Link]

They didn't initially do the M4 feedramps. Colts commercial products are rife with a hodge podge of parts from transition periods. The military would get the revised models per the contracts and civilian models got whater was left or available. Don't assume it's not original. The slabside lowers were used in commercial products long after the military switched to A2 lowers. The 1/9 M4 barrel is different.. All I can think of is that it may have been produced prior to the adoption of the XM4 1/7" It may be pre M4, and post M16A1 commercial. They sold many slabside with A2 uppers commercially. The 1/9 could have been preproduction XM4 barrels. The originals didn't have M4 ramps in the uppers until later.

Interesting, thanks for the info!

 

[Boboclown]

They didn't initially do the M4 feedramps. Colts commercial products are rife with a hodge podge of parts from transition periods. The military would get the revised models per the contracts and civilian models got whater was left or available. Don't assume it's not original. The slabside lowers were used in commercial products long after the military switched to A2 lowers. The 1/9 M4 barrel is different.. All I can think of is that it may have been produced prior to the adoption of the XM4 1/7" It may be pre M4, and post M16A1 commercial. They sold many slabside with A2 uppers commercially. The 1/9 could have been preproduction XM4 barrels. The originals didn't have M4 ramps in the uppers until later.

Kinda figured. Some stuff I just can't say without being around then.