Ambient colour white will make the thing glow, I think perhaps you mean Highlight white? For metals I'll usually use a pale grey as the highlight, but never an ambient, that stays black. Excuse me for contradicting you but that sounds very strange. For polished effects you need a reflection map for something like a sword blade, for gun metal check out Maclean's reflection maps in 3DCommune free stuff, there's some very useful reflection maps in his pack. One of which can be changed to a blue wash for gunmetal. Armour is the same, low level reflection settings with highlight to white or pale grey, texture colour to white if using a texture map or pale grey if just using colour and reflection to white. I'd advise you leave the ambient settings alone.