This Bear Creek Arsenal AR-15 10.5" M4 contour, stainless 5.56 barrel has a carbine length gas system with a 1:7 twist. Our 5.56 stainless rifle barrels are made from the finest 416R Stainless Steel and precisely rifled for high accuracy at a great price. Use a Bear Creek Arsenal ar barrel in your next AR15 build and experience superior performance backed 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. Visit our YouTube channel to see our AR15 and AR10 barrels in action and get answers to common questions about your gun. Shop more 5.56 NATO Barrels! We recommend Point Boat Tail 75 gr. Or Nosler Match Grade 69 gr ammo. {{widget type="Magento\Cms\Block\Widget\Block" template="widget/static_block/default.phtml" block_id="42"}} Does not include gas block or gas tube