a neighbor  has what he says is a AR-15 upper receiver for sale. He says its an SP-1. He says it's from the mid 60's and was military issued and not a civilian model. It has a 3-prong flash sup. triangle hand guards, bayo lug, no foward assist etc. It has markings or stamps on the upper, near the ejection port a "C"  in a square and what looks like a V P in a triangle or forming a triangle. Is there anyway for me to tell how old this upper is from its markings? and either way...what is it worth? thank you in advance.

Dave

Sounds like a Colt made Air Force M16 upper, if the front pivot pin hole is small and the left side is counterbored it's Air Force ...Value with no bolt, carrier or charging handle and in exc condition around $ 200-250ish add $ 100 if it comes with bolt carrier assy and charge handle..

Thank you for your reply. Does the V P marking tell you it's air force? sorry, but not sure what you meant by "left side counterbored"? Is there anyway to tell age of this upper? If it is govt issue shouldn't it be worth more? ... Just curious.

Thanks again,
Dave

Quoted: Thank you for your reply. Does the V P marking tell you it's air force? sorry, but not sure what you meant by "left side counterbored"? Is there anyway to tell age of this upper? If it is govt issue shouldn't it be worth more? ... Just curious. Thanks again, Dave

V in triangle? is a colt inspector mark. Here's a pic of an Air Force A2 upper. Look closely at the front pivot pin hole and note the counterbored hole. All AF uppers are like this so they can be interchangeable with the Early Colt/Armalite Ar15 Mod 01 type lower recvrs that used a front pivot pin with detent ball. There's tons of AF surplus uppers floating around so they aren't really worth more but they are small pin so you don't have to use a pin adapter like the SP1 uppers ..

Thanks again....I got it now. Thanks for your help.


Dave

On the other hand, given the description, it may well be an early SP1 upper.

The difference between the Air Force surplus pieces and the commercial SP1 jobs is solely in the size of the front hinge hole.  The Air Force surp units will fit a current lower unaltered.  The SP1 has a larger hole in front, and will require an adapter sleeve to make it fit.

Also, there should be some markings on the barrel, ahead of the front sight base. It will at least be stamped  C MP.  That's the early model unplated version.  It may be stamped C MP C, or C MP B.  The first is a barrel with a chromed chamber. The "B" stamped barrels have a fully chromed bore.  The very lastest versions were stamped C MP CHROME BORE, but given that the thing has a three prong suppressor, it would almost certainly be too early a produced piece for that.

Thank you "shamayim" I went to the guys house and took another look. It does have a counter bored pin hole. I checked for barrel markings. I found some on the barrel between the front site posts. I only see C M P  ... Thats it. I checked the bore, it looks chromed (or is it just shiney metal?) The chamber does NOT  look chromed (or shiney). He has the stock for it. It does not have a trap door just a ribbed rubber(?) recoil pad. is it an early one?

Is it worth  the $300. he wants for it?

Thanks again to you both,
Dave