M4 STRIPPED BARREL | Brownells Link above shows specs. If link doesn't work then this is cut from page: Stripped, M4-profile 16" barrel delivers features you expect to find on a premium-grade rifle at a remarkably economical price. Machined from ordnance-grade 4150 chromium-molybdenum alloy steel for exceptional strength, and magnetic particle inspected (MPI). Chambered for 5.56mm NATO, with 1-7" right-hand twist cut rifling in the chrome-lined bore. Includes pre-installed barrel extension, with M4 feed ramp and locator pin. Gas port is drilled and muzzle is pre-threaded to accept ½"-28 tpi accessories. Would like $140.00 cash.