You need to shoot at the place where the castle and they open. You can also open locked cabinets (green - changing room). Hinged locks on the doors are broken by shots. Do not pass by! Break them! Inside the cartridges come across, sometimes rare. So with the cartridges there will be no problems.
You buy them, persist, and then immediately load on the same SAVE, and this merchant has ammunition. There is such a chip, let's say that you need the cartridges what you need, you certainly buy them, but you have little, since all sorts of creatures for Chernobyl walks a lot, and you can not teleport to some city at any time (like B). In the game, the stalker is often case that there is not enough cartridges.
