Yes
No.
No. A standard AR15 has a buffer tube that runs inside the stock that contains the recoil spring.
The stock and forearm were traditional wood, but can be other materials. With the AR15 and M16 rifle, they are made from metals and plastics.
Try AR15.com Try AR15.com
If it is one of the recent Colt .22LR AR15 rifles, then the answer is no - they are completely different internally.
1959
Yes
The US Army presently uses the M4 carbine, a shorter and much modified version of the Armalite AR15.
Colt has not offered a AR15 in 308
It depends.. if you have a carbine length barrel and will be using it on a rifle with a carbine length barrel, then yes. If you took it from a rifle with a rifle length barrel, and are putting it on a rifle with a carbine length barrel, then it won't function properly.
By it's serial number. Go to www.proofhouse.com and under 'long rifles' listing look for AR15 Sporter
@ 40 inches.