Available for In-Store Pick Up One (1) new Sig Sauer MCX Rattler Pistol chambered in .223 Remington / 5.56mm NATO. This pistol has a 5.5 inch barrel with a 1 in 5” twist, PCB (Pivoting Contour Brace), M-LOK handguard, gas piston system with an adjustable gas regulator, one 30 round magazine and comes with the factory cardboard box and factory paperwork.