Depends on your budget, and if you want an entry level rifle or a tactical rifle. That makes a HUGE DIFFERENCE!!!!
If you want a basic rifle, the CMMG Bargain Bin is well worth it. If you intend to impress others with your mall ninja abilities, then Colt, Noveske, or LMT is practically mandatory.
AR15.com has a good listing.
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
By it's serial number. Go to www.proofhouse.com and under 'long rifles' listing look for AR15 Sporter
Depends on model.
@ 40 inches.
Its ar15
Yes