Double asterisk () under Bushmaster, a person on the internet e-mailed me that he had a lower that was shipped stripped (thus not a complete rifle) in 1991 from Bushmaster with serial 0327XX - ALWAYS CALL TO VERIFY. NOTE II: The 1969-1970 downturn (highlighted in purple) in production numbers is due to Colt withdrawing the AR-15 from the market temporarily to fix the 'hammer follow-down' issue (the gun could fire full-automatically - erratically - if.Ĭolt Sp1 Serial Numbers Dates The finest production revolver ever made. The year/serial numbers under Colt SP series was forwarded to me by an individual whose return address I no longer have. The serial numbers listed, except for 1963, 1969, 1970, are the serial number at the first of the year.Double asterisk (.) under Bushmaster, a person on the internet e-mailed me that he had a lower that was shipped stripped (thus not a complete rifle) in 1991 from Bushmaster with serial #0327XX - ALWAYS CALL TO VERIFY. The year/serial numbers under Colt SP series was forwarded to me by an individual whose return address I no longer have.M16A1’s have been observed with serial numbers as low as 604,505, and XM16E1’s have serial numbers as high as 741,12X. Serial numbers in this range were not run in order. This rifle is all original including the Edgewater buffer and three prong flash guard.

There are also a small number of US Air Force M16 Colt's Model 604 found in this serial number range. 223 Made in 1966 Description: Colt SP1 made in 1966, serial number SP 06778. US Property marked XM16E1 Colt's and M16A1, both Colt Model 603.

Colt sp1 serial numbers