I lead a group of Illinois preppers. I know that alone will by no means make me an expert in the never ending debate of which cal. or rifle is best. In my military and law enforcement experience I would suggest that a fire arm is a tool. Just as you would not use a hammer to drive a screw, you would not use a .50 cal to drop a bird. Our group has adopted a standard weapons battery. For urban survival we determined that the pistol will likely be your primary tool. Even in the worst of crisis and mob rule, walking down the street with an M4 slung over your back will likely get you in some manner of trouble or draw attention. We have chosen to use pistols chambered in 9mm. Before people begin with the cursing on caliber, allow me to explain this choice. 9mm is NATO standard and many law enforcement officers still carry 9mm making ammo more common, Ammo is cheaper for a 9mm which helps the prepper on a budget, the recoil on a 9mm is light enough that even the smallest women can handle it, and the 9mm is still considered to be a suitable round to stop a threat. Lastly, in a shooting situation, often you will not be confronted 1 on 1 and with your adrenaline at max and as you quickly move to cover, you will likely not be scoring a hit on a threat with every shot. For this reason the increased ammo capacity of the 9mm allows you to keep firing as you move with less reloading. There is a reason the Military uses the 9mm and believe it or not, its not because "It sucks". That being said, a .22 rifle is an amazing tool. Able to drop small game for pennies a round, it is light weight and very accurate. This may be the ultimate survival caliber (For those who dont want to argue the .410). The .22 is not considered a defense round, in a pinch you could stop a threat with it, but there is an equal chance, especially in the winter when the threat may be wearing heavy clothing, you will just upset him. A shotgun is probably a close second for the ultimate survival weapon. A shotgun can be loaded with a variety of shot from bird shot, to buckshot, to slugs, flechette, sabot, even dragons breath rounds that turn it into a flame thrower. The 12guage is the most common and thus I would suggest this weapon. Remington 870 and the Mossberg 500 are favorites of law enforcement and military and are excellent basic shotguns. If your not on a budget the sky is the limit with this tool. For an Battle Rifle I suggest anything built off an AR platform or as a second choice an AK varient. AR systems in 5.56 are best. A 5.56 can fire a .223 (A favorite with law enforcement) and a 5.56. A .223 chambered can only fire a .223. There are a few exceptions to this, for example rock river makes a chamber known as the .223 wylde which can fire a 5.56. The perks to this weapon system are light recoil, light weight weapon and ammo, fast target aquisition, and accuracy over the AK system. For those who sent the round is not sufficient, check this out --> http://www.timawa.net/forum/index.php?topic=17111.0 If you are too squimish to look, its a grapefruit sized hole and a fractured bone protruding from the leg of a man hit in an army training excercise. The AK system is not without its perks. The rifle's ruggedness is legendary, Maintanance consists of a bootlace with a knot covered in used motor oil being pulled through the barrel. That being said, I have experienced minor malfunctions with the AK, nothing that can not be cleared in 2 seconds, but in a fire fight 2 seconds is a long time. I have a .308 and 30-06 that I like very much, for a heavy caliber the .30-06 will out perform the .308 but the .308 is NATO standard and is likely to be more common in a long term crisis. That said, I see precious few moments an urban survivalist will need such a high caliber rifle. There is no game in the big city that would need that type of round and if for some reason you feel you can identify a target at 900 yards in a city that needs to be shot you need to stop watching all those movies. There is no way you can identify a threat at that range in a city with that many civilians. The key is to remember this, Chicago is not Iraq. You are not a soldier, and if you were, you need to flip that switch off. You will not be shooting someone at 3/4 miles just because they are carrying a rifle, maybe they are just out hunting small game for their family. How would you like it if someone sniped at you for carrying a rifle... which brings me back to why you probably dont want to carry an M4 on your back through the city... full circle and I will leave it there. Hope some of you folks found this helpful, best of luck preppers, God bless and good luck with your preps.