The Swenson 1911 Government Semi Drop-In Barrel is hammer forged over a precision mandrel within .0001" with bore tolerances held within .0002", this barrel is a surefire way to upgrade or replace your old or worn out barrel. This barrel is manufactured from 4140 steel, heat treated to 44Rc and features a bore with a surface finish of 16 microns or better. This barrel also features a National Match ramp. Notes:Swenson is proud to offer this high quality 1911 drop-in barrel, however, due to the vast selection and many different variations of 1911 slides and frames, minor fitting may be required. Outside diameter measures .579" held to a tolerance of .001". Barrel link and link pin sold separately. Compensator is permanently installed and cannot be removed.