It's a tactical rail about the higher receiver and an adjustable stock. The DEF10 has a single stage set off and includes just one 20-spherical Magpul PMAG. It has an MSRP of $999 as well as comes along with ArmaLite’s limited life time warranty.Like the AR-10 and AR-fifteen, the AR-17 featured a barrel extension to the bolt to lock into, which r