The Luth-Ar Rifle Kit Bull 16 W/ Fixed Stock combines precision craftsmanship with versatile AR platform components to deliver a complete build experience centered on a 16" fluted bull barrel upper with a 15 KeyMod palm handguard, ready to pair with your choice of MBA-1 fixed rifle buttstock assembly or MBA-3 adjustable carbine buttstock assembly. This kit includes a full lower parts kit and an assembled 16 fluted bull barrel upper featuring a 16-gauge 416 stainless steel barrel, threaded 1/2x28, a .936 gas block, a 16-inch gas tube, A2 flash hider, M4 feed ramp, 1-9 right-hand twist, six lands and grooves, and a button-broached, rifle-length gas system, all designed to maximize reliability and accuracy. Optional add-ons like the Velocity Drop-in trigger or The Lower Enhanc-AR Kit let you tailor trigger pull and overall feel to your preferences, while the included LLRPK-1 Complete .223/5.56 Lower Receiver Parts Kit ensures you have the critical components to complete the build once you source your mil-spec stripped lower. Note that the kit does not include the lower receiver, so youll supply a compatible lower from a trusted source to complete your AR setup.