Easy to install drop-in design; Advanced proprietary broach cut design specifically engineered for increased accuracy potential; Broach cut 6 groove rifling allows for all ammo types to be used safely, including cast lead; 9mm 1:10" RH twist rifling; Special deep style target crown for non-threaded versions; SAAMI spec chamber; Improved overall fit from OEM with added chamfers, improved radius cuts, and other additions for a better than OEM barrel; Improved feedramp design over OEM for more reliable feeding of defensive ammo; 100% Designed and manufactured in the USA with USA sourced certified 416R stainless steel