Assuming SHTF and one needed a defensive rile, please help me find a relativley Cheap ($750 & under) Semi-Auto Rifle that would be a good for SD purposes. I emphasize cheap and prefer it to be $500 and under but would be willing to go to $750. This rifle would not be for hunting, purely Self Defense. I don't really know too much about rifles aside from a few Bolt action Deer rifles. Please let me know what claiber I should be considering and what type of capacity, features, etc I need to look for. I welcome your reccomendations. Thanks, in advance.