They will match the contour of the barrel they take off if you don’t specify a barrel contour for the new barrel. If the barrel contour that you want isn’t something they can copy, then they need a drawing for the custom contour. Having said that, they should have contacted you if they didn’t have a drawing that they could use. Their customer service, how should I say, leaves much to be desired. At least you have a lighter barrel. You can get the Stocky’s carbon VG for your lite barrel contour. In fact they are running a special discount right now: Use coupon code 30rokslide to take 30% off