From the color to look and attributes. To customize it should be point based. For example: 200 pts to distribute on attributes. The higher the rate of fire, the more points it'll cost and so on. You should be able to choose from a large pool of perks and allowed so many. There's many possible ways but I think this is possible.
English
#Destiny
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Removes all the element of chance from drops. After a few weeks and a couple of YouTube vids everyone will end up running with the same stats on their weapons