Machined from aircraft grade stainless steel forgings and heat-treated to R/C 40 for maximum service life. Critical tolerances are held to less than .0005" to provide phenomenal accuracy (test barrels at the Wilson factory routinely shoot groups of 1/2" at 25 yards). Barrels are slightly oversized in the lock-up areas and require fitting by qualified gunsmith. 1911 barrels include barrel bushing. Additional bushings available separately.