Economical, high-quality M4 barrel extension is machined to mil-spec standards with integral feed ramps and predrilled locator pin hole for fast, easy barrel installations. Machined from 8620 steel and head-treated for additional surface hardness to resist erosion by hot combustion gases for years of reliable service. Great for custom barrel jobs and caliber conversions.

SPECS: 8620 steel, in-the-white. .8125"-16UNF thread. Barrel locator pin required, not included.