[Bill Douglas]

I don't think it is this.. . But still worth a try. Maybe your cases are not being resized enough and they are not seating the last 100 microns into the cylinder. And when the hammer strikes it, it moves it forward slightly nstead of it being a full blown whack on the primer. Try using the micrometer to compair your case sizes (and bullet length) against a factory load. Also a good scrub of the inside of the cylinder occasionally doesn't do any harm.