Stern Defense 9mm Bolt Features The Stern Defense 9mm Bolt is machined from 8620 AISI steel and finished with a nickel-boron over mag-phosphate hybrid treatment that improves lubricity and resists corrosion during extended use. This finish combination reduces friction during cycling which helps the bolt run smoother and stay cleaner between maintenance intervals. Its design caters specifically to single-stage triggers with short resets aligning the bolt s geometry with the way many PCC shooters tune their trigger systems for faster follow-up shots. The bolt is also compatible with the JP silent capture spring giving builders a path to a quieter smoother-cycling 9mm build. Built to function with both Colt SMG and Glock pattern magazines this bolt gives AR15/M16 pattern 9mm builders flexibility in choosing their magazine source without sacrificing reliability. It ships fully assembled with the firing pin spring retaining pin extractor and extractor spring already installed along with the proprietary center and roll pins needed to complete the bolt assembly. The bolt is also compatible with the Law Tactical folding stock adapter letting builders fold their stock without removing the bolt carrier group. At 15.5 ounces the Stern Defense 9mm Bolt is a complete drop-in upgrade for Mil-Spec and Glock-pattern 9mm AR uppers available for sale at GrabAGun. Stern Defense 9mm Bolt Specifications Manufacturer: Stern Defense Model: 9mm Bolt Caliber: 9mm Compatible Hosts: AR15/M16 Material: 8620 Steel Finish: NIB / Mag Phosphate Hybrid Weight: 15.5 oz Available At: GrabAGun