the thing with shocker stuff is, that most people buy the HE bolt kit from smartparts, there is the NDZ kit, but there arnt many retailers, there is also the evolve kit, but they are hard to come by as they dont make them any more. There is a new bolt. the eigen bolt. It is being made in the states and aparently is going to match the effciency of most other high end guns, possibly 1800-2000 using a 68/45. What kind of bolt guide do you want, a stock one or a aftermarket?