This Bear Creek Arsenal AR-15 16" Black Nitride M4 Contour barrel with a 1:8 twist rate and Carbine length gas system. Our 6.5 Grendel black nitride rifle barrels are made from the finest 4150 Chrome Moly Vanadium and precisely rifled for high accuracy at a great price. Use a Bear Creek Arsenal AR barrel in your AR15 next build and experience superior performance back by a lifetime warranty! All finished barrels go through a 100% inspection process. Inspections Equipment includes CMMs and Air Gauges for the bores as well as visual and machine inspection. Shop more 6.5 Grendel Barrels! We recommend Defender 107 gr., Federal Gold Medal Berger 130gr. {{widget type="Magento\Cms\Block\Widget\Block" template="widget/static_block/default.phtml" block_id="42"}} Does not include gas block or gas tube