They come in various lengths, dependent on the buttstock and barrel length.
By it's serial number. Go to www.proofhouse.com and under 'long rifles' listing look for AR15 Sporter
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.
Some words with a long "a" sound spelled with "ia" include: Liars Dial Liar Crier
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
@ 40 inches.
Yes
The AR15 series
Its ar15