Rocketman is completely correct. Take it from another ordnance and propulsion expert. The proof houses carefully measure the metal in critical places then fire a proper load. They then measure for ANY change of dimension (plastic deformation). If there is ANY, it fails. You might just cause some (plastic deformation=damage) and not know it. There are fine smokeless loads at very low pressure (3200-4200 psi). Check out http://www.imrpowder.com