Identical to the standard drop-in Ed Brown barrel, but longer length and threaded for use with suppressors. Thread size is 1/2" x 28 tpi RH. Includes link, link pin, bushing and thread protector. Barrel accuracy comes from using the highest quality materials and manufacturing methods. Ed Brown Products is committed to both. The barrels are made from T-416 modified, gun barrel quality stainless steel bar stock, just like a benchrest rifle barrel. T-416 is certified pure, there are no foreign materials, and no hard or soft spots to worry about. It is stress-relieved and heat-treated prior to final rifling and refinishing. Ed Brown barrels are precision machine cut from a 3 pound chunk bar of this top quality steel. Ed Brown barrels are rifled by precision broach in the original six lands and grooves, one turn in sixteen, left hand twist as originally designed by John Browning. This deep cut, broached rifling gives superior accuracy with all types of bullets, including lead. Ed Brown barrels are heat-treated by an aerospace certified heat treat facility, and sub-zero frozen for maximum strength and stress relief. This means more accuracy and longer barrel life to the shooter. Ed Brown has also cut the dimensions to max tolerance on the outside of the barrel. This means less fitting work for you, and more accuracy.