Fallout 3 was good.
This game looks like it will be a mix between STALKER (the semi-realism) and Fallout 3 (the open world). Could be real good. Unfortunately, the game
will have monsters. But if it has a huge, good-looking open world to freely explore, and good dialogue and interesting missions, I'm willing to look past that. Let's hope it won't have laser guns and unrealistic RPG elements.
I kinda like what they did with the guns, it's very original and they somewhat make sense as well. In a post-apocalyptic world, I bet the arms industry would be gone as well. There would still be weapons (the most reliable ones

), but ammunition would soon run out. And the weapons might fall in the hands of the strongest people. As a result there would be a shortage of guns and ammunition, so they would have to be made from scratch. Amateur gunsmiths make new guns, develop new cartridges and magazines.... and there you have it, home-made guns!

At least, that would be my explanation.
I think the guns are very cool and quite realistic actually.
EDIT: that train cart ride at the end of that clip, Stalker reference?