Simply put, the AR-15 really is one of the best defensive tools in today’s day and age. It offers you less recoil than a shotgun, better stopping power and velocity than a handgun, and superior range than either of them. Even for defending your home indoors, the AR-15 is arguably a superior weapon than a shotgun, as it has much less recoil. For defending your property as well, an AR-15 or any other form of semi-automatic rifle that fires an intermediate cartridge such as the .223 will be a good choice. .223 also has far lesser odds of breaking through walls than heaver rounds such as .308 Winchester.
All of this is also not to mention the fact that the AR-15 is fundamentally a very easy weapon to shoot. It has a low recoil, is very ergonomic, and the controls are all very easy to reach. Women in particular can easily use the gun for defense. The AR-15 is also very customizable and you can add furniture and accessories to it to your liking, such as a more comfortable stock or forend or lights and lasers.
Finally, the AR-15 is also much more affordable than you may think. As little as a decade ago, it would be difficult to get an AR-15, at least a quality one. Today, however, buying a quality AR-15 for the $400 to $500 range is much easier than it’s ever been. Examples include the Del-Ton Echo, the Smith & Wesson M&P15 Sport II, and the Ruger AR-556.