Buy Beretta PX4 Storm Type F Full-Size 40 S&W Pistol with Inox Finish Online. Designed to meet the most stringent military standards, the PX4 has been reported to fire well over 150,000 rounds with zero part breakage. The steel and polymers used to create it were developed to exceed the most impossible standards. And with its rotary-barrel design, the PX4 dissipates recoil away from the hand and greatly reduces muzzle jump—making it accurate, pleasant to shoot and lightning-quick on target.