Home Forums Reloading Big Game Rifles ????Pressure Signs????

Pushing the shoulder back too far (.002" +) is usually the cause of primer flattening. The case moves forward upon primer strike/ignition, the case grips the walls, the internal pressure pushes the primer back to the bolt face, the case head pushes back to the bolt face flattening the edges of the primer



limit your case movement by pushing the shoulder back a minimal amount

.010" is too close unless you have absolute control over seating depth. Seating depth can vary +-.005" depending upon how you sort your bullets and how well you control your seating pressure. i.e. your press has linkages that compress and back pressure from seating pressure can lengthen you CBTO (case base to ogive). Conversely, a bullet that seats easier than others can be seated deeper.

You can minimize the pressure variances by moving further from the lands which decreases pressure



If you are seating .030" or .060" off the lands then +-.005" CBTO measurements will not cause problems like seating close to the lands