Yes, if you replace the upper receiver.
Not recommended.
If it is one of the recent Colt .22LR AR15 rifles, then the answer is no - they are completely different internally.
$800.00
50-1200 usd
I just purchased one from a dealer in like new condition for $1,000. I believe that to be the low end of the value of this gun. Most in this condition will be higher.
Depends on condition, etc. Price range from 500-1000
100-1000 USD or so depending on specifics.
It depends on several things. Caliber Brand Material If you want a long lasting, decent one. Plan on spending around 1,000$ If you want a cheap, .22 caliber one, Mossberg sells them around 300-400$
1977. Value depends on conditon and accessories. Range 500-1100
Depends on the application. If you mean power, the higher the caliber, the more powerful it is. for example, a .22 caliber rifle is much less powerful than a .50 caliber rifle.
Made 1974 if sn reads SP33829. Value depends on condition. Range from 500-1000
The AR15 is a 5.56x45 rifle. Incidentally, it is also capable of chambering and firing the .223 Remington, which is similar in dimension, but the two are not identical. That's the norm. AR15 rifles can be had in a number of calibres nowadays, to include 6.8x43 Remington SPC, 6.5 Grendel, .458 SOCOM, .50 Beowulf, 5.45x39, 7.62x39, .204 Ruger, 9x19 Parabellum, .40 S&W, .45 ACP, 6x45, .450 Bushmaster, and others.