Just saw this while looking up primer brisance.
http://www.castingstuff.com/primer_t..._reference.htm
"Another thing that is not in this test, but I have noted, is using a newsprint wad over the primer. This keeps grains of powder out of the flash hole. It seems to even out the ignition by eliminating a variable (sometimes with grains in and sometimes without grains in, or a variety of combinations)."
Never heard of doing this.
I does make sense.
Anyone tried this????