Hi I have a excellent Bushmaster 14.5in M4 barrel assy. 1/7 twist, M/P tested, 5.56 chamber. Chrome lined. Std. 1/2x28 threaded. M4 feed ramps. Comes with barrel nut, danels defence Low profile gas block. Carbine gas tube and roll pin. Barrel was creaokated Magpull FDE. Shipped $150. Money orders, personal checks or paypal +fee/gift.