Please note that they were the NRA's words, not mine.
"
Tinkering
If you like to tinker, the AR-15 is the rifle for you. Aftermarket parts and upgrades are readily available from hundreds of sources, and the gun’s easily understandable operation system makes it simple to work on. If you can’t build one of these rifles on your kitchen table with just a few specialized tools (legally, of course), you probably skipped shop class in high school. Installing new stocks, triggers, hand guards, pistol grips and other parts is also a breeze."
