The UDP-556 has all the features that you are looking for in the AR-15 platform. Chambered in 5.56 NATO, it features a 16" chrome moly barrel with a 1:7 twist and is threaded to 1/2x24, giving you the ability to choose from a number of aftermarket muzzle devices. In addition, the UDP-556 comes standard with a B5 Systems SopMod Stock as well as a B5 Type-23 grip. This rifle is comfortable to handle whether you're a casual shooter or a serious competitor. All models also feature a free floated barrel with a 16" ultra light M-LOK handguard.