Suggested Gear
The 72 Hour Combat Load
Rifle
Should be semi-auto, but rule number one of a gun fight is: "Have a Gun." Should be of a common caliber e.g.. 7.62x39, .308win, .223rem. Military surplus are also perfectly acceptable, but you should bear in mind that ammunition may well become scarce, and 8mm and .303Brit should be well stocked if you opt for one of these calibers.
Group Standards, { if possible, in order }
a) AK47 or Clone 7.62 x 39
b) HK91/G3 or Clone .308
c) SKS 7.62 x 39
d) AR15 / M16 or Clone
Sidearm
If you choose a secondary weapon, it should be of a major caliber. 9mm, .40S&W, or .45acp for semi-autos, and .38spl/.357mag for revolvers are going to be the most common. Be sure to choose a reliable handgun with a well established reputation. A 1911, 92FS, Glock, or Smith&Wesson would serve you well (as would many others).

Please indulge me while I go off on this tangent, and speak a few words about weapons. Generally speaking, you get what you pay for when it comes to arms. Good guns are not cheap and cheap guns are not good. While you may find the occasional steal of a deal, this is the exception and not the rule.

Since you are buying a gun to defend your rights and quite possibly your life, isn't it in your best interest to procure the very best rifle/pistol/shotgun you can afford? If you only plan to spend $100 on your main battle rifle, don't be surprised if it shoots like a $100 rifle.

It bothers me to no end when I hear well meaning Patriots complaining about the cost of arms. I am not a dealer, so I have no vested interest in the profit margin of the guns we buy, but I do have a vested interest in preserving my own hide.

If you are currently without arms, and you are looking at buying that $60 Mauser, that is fine (remember, rule number one of gunfighting "have a gun."), but you should be saving your pennies to buy something more substantial. I understand all to well that Patriots are more often than not, 'not men of means.' But, even if you are getting by on bread and water, you can still squirrel away funds for that MBR...I did.