Geissele Cold Hammer Forged .300 BLK 8" Chrome Lined Barrel 05-3428 is built around the same forging process that anchors every barrel in Geissele's lineup, cut to a length that makes the most of 300 Blackout's dual-purpose ballistics. Cold hammer forging compresses the rifling into the bore under extreme pressure rather than cutting it, producing the kind of consistency that holds accuracy steady across supersonic and subsonic loads alike. This Geissele 300 blackout barrel carries a 1:7 twist in Geissele's tapered profile, chambered specifically for 300 BLK's wider bullet-weight range — from lightweight supersonic rounds up through heavy subsonics run suppressed. A custom pistol-length gas tube pairs with a Super Compact Gas Block for precise alignment, while Geissele's Phased Array® Gas System with the Tri-Port™ System meters gas flow to keep cycling smooth across that same wide spread of ammunition. Chrome moly vanadium steel forms the base material, chrome-lined bore included, backed by a manganese phosphate exterior for added corrosion resistance. Every Geissele barrel at this length goes through High Pressure Testing and Magnetic Particle Inspection before it ships, catching flaws that wouldn't surface until the barrel was already in service. M4 feed ramps round out the build for reliable feeding regardless of magazine type. Key Features: 8" length, 1:7 twist, 300 Blackout chamber Cold hammer forged rifling, chrome-lined bore Geissele Taper Profile contour Custom pistol-length gas tube w/ Super Compact Gas Block Geissele Phased Array® Gas System w/ Tri-Port™ metering 5/8x24 muzzle thread Manganese phosphate finish High Pressure Tested and Magnetic Particle Inspected 05-3428 puts full-size CHF quality into an 8" barrel built specifically to get the most out of 300 Blackout's dual-role ballistics. Geissele Cold Hammer Forged .300 BLK 8" Chrome Lined Barrel 05-3428