To longrifle1000: I kind of understand what you mean. It would be better to bump the shoulder back the exact amount so that the casing would headspace on the shoulder. How would you measure that? Doesn't most dies set the casing back to close to minimum? It would have to be exact. If not then the bolt would not close, or it would close tightly? I believe most people shoot factory loads, and I am pretty sure the factory could not know the measurements of all the different chambers? Again it would have to be exact, because the belt would stop the cartridge from going in any farther. Wouldn't it be the same with rimmed cartridges? like the 30-30? I am going to have to look into this. Sounds like fun. Tom.