Preban Colt sp1 car-15

[leman]

Trying to find some info on this rifle that my uncle left me. Haven't seen many sp1 carbines and haven't seen any others with the 3 prong flash hider. Was this a factory option or do you think it was added later?

Thanks in advance

[48J]

The three prong flash hider was the original flash hider for the M16. The birdcage hider was adopted later partly because one of the three prongs would bend and damage performance.

That is a nice looking carbine.

[scottryan]

The barrel and stock on that gun are not Colt.

That is most likely a full size SP1 rifle that someone tried to convert to a carbine.

Gun is worth $1000 at best in that condition.

[leman]

The barrel and stock on that gun are not Colt.

That is most likely a full size SP1 rifle that someone tried to convert to a carbine.

Gun is worth $1000 at best in that condition.

Thanks for the info. I had doubts that the stock was original since it's plastic and most colts came with aluminum, but I also had heard in the later years they came with plastic ones. Mind dates 1980 so wasn't positive. Why do you say the barrel is not colt though?

[scottryan]

Thanks for the info. I had doubts that the stock was original since it's plastic and most colts came with aluminum, but I also had heard in the later years they came with plastic ones. Mind dates 1980 so wasn't positive. Why do you say the barrel is not colt though?

The barrel is not a lightweight profile barrel. It is an aftermarket gun show special barrel that floated around in the 1980s.

The barrel should be lightweight profile marked

C MP B

or

C MP CHROME BORE

The delta ring and handguards are not colt.

The entire stock assembly including the tube, backplate, and lock ring is not colt.

Someone robbed the Colt parts off of that gun to sell them for money. They installed aftermarket junk and then passed the gun off as Colt factory. This was and still is a common scam.

[scottryan]

I would also suspect the bolt carrier group has been switched.

A colt bolt carrier group will be marked with a C on the left side of the carrier and MPC on the bolt.

[scottryan]

Colt plastic stocks are not molded like yours. They have different profiles and contours.

[Renegade04]

What would be nice is some pics of the right side of the upper receiver, especially around the rear sight and the left side of both receivers. Also a pic of the barrel markings (if any). The Delta ring is incorrect. It should have a flat ring. The FH and the stock are not correct as well. The FH should be an A1 birdcage and the stock should be aluminum with the smooth vinyl acetate finish. It should also have one of the early buffer tube locking nuts ("castle nut"? that has the round holes and not the notches. The buffer tube should be a 2-position type. The barrel should be a lightweight "pencil" profile with a 1/12 twist. It does appear to be a hodge podge of parts.

[leman]

Thanks for all the info guys. My guess is the bolt has been replaced since it has forward assist serrations, but it is still stamped with a C and has MPI on the bolt. Upper receiver is stamped C M.

Like I said this is one of the guns that my uncle left me so it's not like I'm out any money. He was a lawyer that would do work for guns and other random stuff. Who knows if he put this collaboration together or someone paid him with shorting him money.

[scottryan]

Thanks for all the info guys. My guess is the bolt has been replaced since it has forward assist serrations, but it is still stamped with a C and has MPI on the bolt. Upper receiver is stamped C M.

Like I said this is one of the guns that my uncle left me so it's not like I'm out any money. He was a lawyer that would do work for guns and other random stuff. Who knows if he put this collaboration together or someone paid him with shorting him money.

A serrated carrier is correct for that gun. Colt stopped making slick side carriers in the late 1960s.