Estimates suggest that there are approximately 15 to 20 million AR-15 rifles owned in the United States. However, the exact number of individual owners is difficult to determine due to varying reporting practices and the lack of a national firearm registry. The AR-15 is one of the most popular rifles in America, often favored for its versatility and customization options. Consequently, the number of owners could be several million, reflecting the rifle's widespread appeal.
As many as the magazine is capable of holding.
IIRC, they mention it on their web site.
Owners of America - 2010 was released on: USA: 5 May 2010 (limited)
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.
how many owners has it had?
1959
Yes
The king of England
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
The cast of Owners of America - 2010 includes: Nichole Jackson as Megan Cantebury Jones as Emily