Re: SHTF Scenario
How can anyone say that 7.62x39 needs range to BECOME effective? This may be true of FMJ ammo in some bizarre way that I've never considered, but with HP or SP ammo, velocity = effect.
I doubt that "real battle" has very much of anything to do with SHTF, though one can also imagine that every conceivable scenario would be played out, all over the place. If there are organized military units fighting against civilians, Rambo will be that guy who died tired, because he was running.
I think random and very localized battle will be much more common, in a state of general anarchy/chaos.
Run with any scenario you prefer.
As for grabbing what you need, I think it's vitally important to figure that out beforehand. If you have 28,000 guns in the safe, it won't mean a thing unless you have picked out ONE rifle, ONE pistol, and a decent ammo supply for each.
If you keep a bug-out bag, that's even better.
Let's just imagine that you're at work one day, around 2 pm, caught up in whatever you're doing. One of your fellow workers comes by and tells you that there's something big going on. There are fires at the airport, and fighting in town. How long would it take you to get your whole act together, and be ready to engage hostiles from your prepared defensive position?
Around here, we don't say "Oh shucks", or "oh man". We say Oh BAMA!!