New for 2018 is the 12-gauge Mossberg 590M "Shockwave", a magazine-fed version of the hugely successful Model 590 pump-action shotgun line used by military, security/police, special forces, and civilian gun owners across the world. The Model 590 line has proven ultra-popular across various markets for its reliability and man-stopping firepower at close-to-medium ranges. The M-models bring about considerably increased reloading speeds, for a shotgun-type weapon, and an increased ammunition-carrying capability.
The Model 590M was first announced at SHOT 2018 in Las Vegas.
The Model 590M retains the form and function of the proven Model 590 line with the notable exception being the curved detachable box magazine extended out from under the forward section of the receiver. The magazine is inserted into a well directly ahead of the trigger group. The shoulder stock integrates the pistol grip and a large ejection port is featured at the right side of the gun body. The slide sits on the lower tube which doubles as a spring-loaded tube magazine. The barrel sits over this tube in the usual way. Iron sights are fitted for ranged fire.
The centralized positioning of the magazine in the 590M makes for a better balanced long gun leading to enhanced accuracy. An ambidextrous safety system is featured as is a drilled-and-tapped receiver design, a heavy-walled barrel assembly, and dual extractors. All this leads to an exceptional Close-Quarters Battle (CQB) weapon for even the most discerning of customers.
Ammunition capacities range between 5-, 10-, 15-, and 20-shot designs held in a patented, spring-loaded, double-stacked magazine - said to be the first for shotguns anywhere in the world. Stabilizing ribs help to guide the magazines into place each and every time for certainty in the locking procedure. A release button is positioned ahead of the trigger to release the magazine from its well and this is made ambidextrous to accommodate different shooters.
There are currently (2018) three major models in the Shockwave line. Two feature full shoulder stocks (s/n 50205 and 50206) with the third (s/n 50208) having a pistol-grip-style assembly. All are 12-gauge-chambered. The 50205 and 50208 have a cylinder bore choke with the 50206 having a cylinder Accu-choke system. Sighting in the former pair is of the bead-type while the 50206 has a ghost ring. All come in a matte blue finish with the 50205 and 50206 having synthetic black stocks. The 50208 has a "Raptor Grip" corn cob forend with accompanying strap. The 50205 and 50206 have an overall length of 39.5 inches with respective weights of 7.75lb and 8lb. The 50208 has an overall length of 27.5" with a weight of 6.55lb.