We have been working on this project for a long time. We are some of the very few companies that actually produce our own barrels in house (right here in Salem, Ohio). This barrel is for the older p320 compact models, X carry models, and any of the other 2 million Sig variants that use the 3.9" barrel. The LCI has been removed from these barrels to reduce gas and carbon from fogging up any optics. Anyone with an LCI on their 320 can remove it and make our barrel work for them. Fits the Sig P320 Compact, X-Carry (minor fitting may be required on some X-Carry models), and M18 (will not fit the X-Compact). Easy to install drop-in design. Advanced proprietary broach cut design specifically engineered for increased accuracy potential. Higbee thread for stronger threads that limit cross threading  Broach cut 6 groove rifling allows for all ammo types to be used safely, including cast lead. 100% Designed and manufactured in the USA with USA sourced certified 416R Stainless Steel.  9mm 1/10RH twist rifling. Special 11 degree competition style target crown for non-threaded versions or 1/2x28 threads with included thread protector on threaded versions. Threaded versions include Viton high heat integral O-ring lock thread protector. SAAMI spec chamber. Improved overall fit from OEM with added chamfers, improved radius cuts, and other additions for a better than OEM barrel. Assorted specialty coatings and finishes to choose from. Light fitting may be required for some X-Carry models. Lifetime performance warranty for function.