every time i create a new item collecton in guerilla i link it to the .weapon
but i cant place it in a map with sapien...help

when you make an item_collection file save it in the item collections folder inside of the tags folder.
you need to add your weapon in sapien then add the item_collection file..you add the item_collection file in the properties palette.you won't see you weapon in the sapien game window.but when you compile your map you will see your weapons ingame.