AR15 Gurus. Need help identifying an old Colt upper receiver

[ChrisK]

I'm trying to clean house with some of the extra parts and things that my dad handed down to me when he died. I stumbled onto this upper and need some help determining the model, year, and the value of it.

I snapped some pics, if you want me to take any more of certain areas, let me know. Trying to fund a 300 Blackout project!

Thanks!

EDIT: found the buttstock if that helps.

Another edit: Found the BCG (I guess it's the right one)

Don't see a firing pin retaining pin.

 

[SpeedRacer]

Looks like a Colt SP1 upper. I've seen them go for around $450 with original BCG and charging handle. Not sure if you'd be able to find a year on it since it's not serialized.

 

[ChrisK]

I think I have the bolt carrier, but haven't found a charging handle. Damn, I'd like to get 450 for it haha.

 

[ChrisK]

found the buttstock. Added it to the first post.

 

[MyTFAL]

I have one like that, I believe they were surplussed Air Force Kits, the lowers were destroyed and the uppers sold pretty cheap. I bought one that someone put on a DPMS lower it shoots very well. The bolt carrier is easy to identify it doesn't have the forward assist gills cut into the side of it. * note* I am no expert.....

 

[ChrisK]

I have one like that, I believe they were surplussed Air Force Kits, the lowers were destroyed and the uppers sold pretty cheap. I bought one that someone put on a DPMS lower it shoots very well. The bolt carrier is easy to identify it doesn't have the forward assist gills cut into the side of it. * note* I am no expert.....

So that BCG is not for that upper, since it has the gills cut out.

 

[MyTFAL]

I dont think the uppers came with a bolt carrier mine does not have a slick side carrier in it either but the originals did not have gills they had no fwd assist so no need for the "gills" once again all internet hearsay I am no expert.

 

[SpeedRacer]

Could still be it AFAIK. Is there extra material removed below the rear of the firing pin?

 

[MyTFAL]

Dude you're a lower and a lower parts kit away from a banging retro AR. Nodak offers a slick side lower that would look awesome with this setup.

 

[ChrisK]

I dont think the uppers came with a bolt carrier mine does not have a slick side carrier in it either but the originals did not have gills they had no fwd assist so no need for the "gills" once again all internet hearsay I am no expert.

Are the SP1 uppers sought after? Or would I have trouble selling it, without the bcg, for $250-300?

 

[ChrisK]

Could still be it AFAIK. Is there extra material removed below the rear of the firing pin?

Yes that's it.

 

[ChrisK]

Dude you're a lower and a lower parts kit away from a banging retro AR. Nodak offers a slick side lower that would look awesome with this setup.

Yeah I know. I've got my heart set on building a 300 blackout surpressed. Don't really like the look of the retro ARs haha. I may keep it if it's not worth selling.

 

[JR1572]

http://www.biggerhammer.net/ar15/

This link is old, but the information is good.

JR1572

 

[JR1572]

So that BCG is not for that upper, since it has the gills cut out.

That's not necessarily true. Does the bolt carrier have a "C" stamped on it?

JR1572

 

[MyTFAL]

I'm not sure why a SP-1 built for the civilian market, would appear to be a kit missing the lower again no expert but the one I have looks exactly like this one only with a modern lower , I was told it was purchased as surplus kit.....

 

[ChrisK]

It's possible that I still have the lower, but its part of a complete rifle. Maybe my dad changed out the upper. I have 4 colt ar15s so maybe one of them has the original lower.

 

[MyTFAL]

Maybe you never know I can't find any other info so I may have repeated bad info,...

 

[Richard in LA]

Just because its a slickside upper, doesn't mean it didnt come from the factory with a BCG with the forward assist notches. I have 3 100% original SP1's that all have the notches. That appears to be an SP1 upper, due to what appears to be a large hole upper, and that should be a correct BCG for said upper. I"m assuming its a large hole upper, can't tell for certain from the picture,

Look and see if you have a slabside Colt lower on one of your rifles, should be marked "COLT AR-15 Model SP1", If you do, its worth more put back in its original configuration, rather than selling the parts off individually.

 

[ChrisK]

Thanks. I'll look for that

 

[nickatnite]

The lower should look or read like this: