What kind of walnut shell are you using that is clogging flash holes? I have never in my life had to dig out a flash hole. I am using the lizard bedding from one of the pet stores in both large and small rifle cases with no problems. Before the lizard bedding I had an old bag of walnut shell that I bought from Dillon in the late 80s. I inspect my cases each time prior to priming and have not experienced this clogging issue of which you speak.
