The Shadow Systems Match Barrel for MR918 has a spiral fluted pattern that reduces the weight of the barrel while adding somewhere for dirt and debris to exit when cycling. It is precision machined to drop-in more easily and fits tights in critical lock up areas. This highly improves accuracy! Threaded to allow the use of a suppressor compensator or other accessories. - All of our barrels are 100% Made in the USA and are custom designed from U.S. sourced materials. - Barrel Details: - 416R Stainless Steel 1/10 Broach Cut Rifling