Made from a one-piece, 17-4 stainless steel forging, beautifully finished to help you achieve the finest in accuracy. Matching stainless steel bushing supplied. Barrel and bushing are left slightly oversized at lockup areas to allow precise final fitting. Chamber requires finish reaming. Hardened to Rc 40. All barrels are .45 ACP and non-ramped except .38 Super which features a Wilson/Nowlin ramp to fully support .38 Super rounds. Mfg: Wilson Combat SPECS: Machined 17-4 stainless steel, heat treated Rc 40. Fits 1911 Auto. All require finish chambering and gunsmith fitting. .45 ACP models are non-ramped and available in 31⁄2" (8.8cm) Officers ACP, 4.25" (10.7cm) Commander, and 5" (12.7cm) Govt./Gold Cup. .38 Super is 6"