The BCA AR-15 Barrel is a 20" heavy barrel profile made of 4150 chrome moly vanadium stainless steel, rifle length gas system, M4 feed ramps with a 1:8 twist rate and is chambered in 6.5 Grendel Type II. Finished Barrels go through a 100% Inspection Process. Inspections Equipment includes CMMs and Air Gauges for the Bores. {{widget type="Magento\Cms\Block\Widget\Block" template="widget/static_block/default.phtml" block_id="42"}} It is the responsibility of the consumer to ensure all state, local, federal, and ITAR regulations are followed Does not include gas block or gas tube