*Please note this excerpt from http://cz-usa.com/support/faq/ The P-01 9mm (designated the P-06 in .40 S&W) was designed for LE and Military duty, but its compact size and the reduced weight due to its forged alloy frame made it ideal for discrete carry as well. Equipped with a decocker, the P-01 provides convenience for those who prefer hammer-down carry. The P-01 was the first CZ model to benefit from updated manufacturing technology at CZs Uhersky Brod factory. The components of the P-01/P-06 are completely interchangable with every other P-01/P-06, with no individual fitting required. This required some very careful re-design so that the reliability and accuracy were not impaired. Since the time of its introduction (designed in 2001, NATO-approved in 2003) the production upgrades have been rolled out to most of the CZ 75 family and several new rifle models as well. The 1913 accessory rail easily accepts any of the industry-standard lights and lasers to assist low-light use. After 3 years of some of the most aggressive small arms testing ever, the CZ P-01 won the honor of replacing the CZ 75s previously used by the Czech National Police. Reliability:  The U.S. Army Mean Rounds Between Failure (MRBF) requirement is 495 rounds for 9mm pistols. During testing of the CZ P-01, the average number of stoppages was only 7 per 15,000 rounds fired. This is a .05% failure rate or an MRBF of 2142! For many years, the P-01 carried an NSN engraved on its frame, making it the first NATO-spec pistol ever available to the public. Recently, the factory decided to upgrade the slide stop spring which in turn means the current models may not carry the NSN.
The Walther PPQ is a feature-rich polymer pistol available in 9mm and .40S&W. The PPQ has a quick action trigger with a crisp pull and .1" reset. The slide and barrel are corrosion-resistant and tenifer coated. The PPQ is also standard with an extended, ambidextrous slide lock and magazine release. The Picatinny-Style accessory rail allows for easy addition of a light or laser. The slide features front and rear serrations while the molded grip has cross-directional texturing and includes small and large backstraps for a more individualized fit.
