I'm in the process of building a 7mm ????????. The stock arrived a few weeks ago and the barrel is on order. The barrel was ordered with a 1:9 twist with the intentions of shooting Berger 180 VLD's. I keep going back and forth between 7mm STW and 7mm Dakota. I've read all I can find on both and performance appears to be equal. Right now I'm leaning toward the Dakota. I like the idea of a shorter, fat case. The action for the build was taken from a Remington 700 7mm Remington Mag. I've read in varios places that the bolt must be modified and the feed rail may have to opened a bit. Can someone explain what modification are needed to the bolt? And, how much feed rail must be removed? I'm the type that I want to know what's being done to my gun when I take it in for work.