If that 35 Whelen Improved chamber is cut properly, you should feel a bit of resistance as you close the bolt on a new 30-06 case. If so, it is easy to do. Take 15 grains of Bullseye, and put it in the bottom of a primed case. Fill the case with Cream of Wheat [Yes the common breakfast cereal, but uncooked of course] Put a wad of Toilet paper or other tissue in the mouth of the case to hold it all together. After you have so charged all your cases, take them out with your rifle to a safe, legal spot, and fire them. You should have perfect 35W Improved cases to load and use. And, no wear to your throat or barrel. Remember to clean your rifle before shooting any loaded rounds through it. Regards, Eagleye.