There are so many ways this could all go down, many scenarios. But, if I didn't know exactly what the situation was going to be and I could carry only 1 gun, I'd choose my shotgun. It's versatile enough to cover many problems, from hunting to self defense. No, it will not cover every situation better than guns made to handle specific tasks, but it can serve in a pinch for just about any function except long distance shooting.

The shotgun is the Saiga-12, which is an AK-47 chambered for 12 gauge, with 5 and 12 round magazines. I can shoot slugs, buck, or bird shot. So, it would serve for self defense with the slugs and buck, small game with the bird shot, or larger game with the slugs and buck. Pretty darn good for just one gun.

My second choice would be the AK-47 or SKS, either way.