I would fix your press & die combo rather than trying to hog out the fine KKM barrel you have.
I agree with the above. The problem with the SDB is that it uses dies that are not common. This is why I prefer the 550b over the SDB. I have been reloading for the .40 for while and I quickly learned this quirk about chambers and the .40 reloading. The Dillon dies are "flared" at the bottom to enhance feeding on their progressive presses. Because of this flare, the Dillon dies do not size down low enough to get the buldge out of glock fired brass or brass fired in a very large chamber. To fix the problem you are having, you can use the Lee .40 standard sizing die or the Lee .40 "U"(undersize) sizing die . The EGW die is the same die as the Lee "U" die.
I would defintely not sand/ream out the KKM barrel. They are very well made, expensive, and engineered to run correcty without any filing or enlarging of the chamber.
