Call of Duty: Black Ops Cold War. The special customization option lets you mix and match blueprint parts to create the beautiful weapon of your dreams ... or something breathtakingly hideous, if that’s more your style. The Gunsmith Customs mode in Black Ops Cold War allows players to create their own weapon designs by selecting pieces and parts from any of that weapon’s other blueprints. That means that if you have an AK-47, you can pull the barrel from one blueprint, the stock from another, and the magazine from a third to give the gun your own personal flair.