Here's What You Need To Remember: The Smith & Wesson M&P (Military and Police) was first introduced in 2005 and as a hybrid of two previous guns, the Sigma and the SW99. Like the rest of the guns on this list, it has polymer frame and steel slide, a large internal magazine (seventeen rounds) and a striker-fired operating system.The 9mm Luger, invented before the Great War, is one of the longest-serving gun calibers in history. Introduced in 1901, it has served in virtually every conflict since then up until today. From World War I’s German army to the British army...