222, 223 and 9mm
Yes
Colt has not offered a AR15 in 308
No such thing. Colt did make some AR15's in electroless nickel.
If it is one of the recent Colt .22LR AR15 rifles, then the answer is no - they are completely different internally.
You will have to call Colt and tell them the serial number.
Call Colt and they will tell you.
Proofhouse.com. Call Colt also.
What is the manufacture date of a Colt AR15 rifle serial number 192754 model SP1
@ 40 inches.
The AR15 series
Proofhouse.com has Colt sn data.
You will have to call Colt and provide the serial number to find out.