The 5.56/.223 Remington rifles can be. Other calibres cannot be, unless the upper is replaced.
Make AR15 parts and rifles
If it is one of the recent Colt .22LR AR15 rifles, then the answer is no - they are completely different internally.
Double Star and CMMG's bargain bin rifles. Some DPMS rifles, as well.
Yes
By it's serial number. Go to www.proofhouse.com and under 'long rifles' listing look for AR15 Sporter
Depends on markings on upper.
The typical AR15 fires the same type of bullet as the M16: a .223 caliber (5.56mmx45mm NATO) round. There are AR-15 rifles that have special barrels made for a variety of popular cartridges, even the little .22LR.
Most AR-type rifles are chambered for the 5.56x45 cartridge - the standard cartridge used by NATO (and also by several non-NATO) forces for their military's assault rifles. They can also chamber the .223 Remington cartridge, although a firearm with a dedicated .223 Remington chamber should not be used for military 5.56x45 ammunition.
Depends on the rifle- some do not HAVE a bolt catch. On the AR15 family of rifles, it is the left side of the receiver.
Don't think so: laws here say you can't have EVEN semi-auto rifles. Let along full-autos.
Depending on the particular model, you can expect $850 for the synthetic lightweight receiver models to $2000+ for the competition and special purpose rifles. They are extremely high quality and as accurate if not more so than any AR15 from any maker. You would do yourself a favor to keep it and learn to shoot it well.
No, but American Firearms and Tromix have made upper receiver for AR15 rifles and carbines chambered in .50 Action Express.