Question: are colt m4 barrels hammer forged?
Answer: In either case, barrels are cold-hammer forged and chrome lined, offer six right-handed grooves with a 1:7" pitch, and a Birdcage-type flash hider affixed to a threaded muzzle. ... All upper and lower receivers are forged out of Type III black hard-anodized, 7075-T6 lightweight aircraft-grade aluminum alloy.