The Geissele Stress Proof Bolt Assembly is engineered for shooters who demand long-term reliability from their AR-15. Built around a forged Carpenter 158+ bolt, this assembly is designed to be stronger and more fatigue resistant than standard mil-spec bolts, and it receives the same rigorous inspection and testing found in Geissele’s Reliability Enhanced Bolt Carrier Group.

This bolt assembly is high-pressure tested, magnetic particle inspected, and finished with Geissele’s Nanoweapon coating for a smooth surface that resists wear and fouling. Ideal for hard-use carbines and training rifles chambered in 5.56x45mm NATO or .223 Remington, it offers a dependable upgrade for range work, duty-style training, or general-purpose AR builds. The included extractor and Geissele’s attention to detail reflect the brand’s reputation for precision machining and thoughtful engineering.

Key Features:

• Manufacturer: Geissele
• Model: Stress Proof Bolt Assembly
• Caliber: 5.56x45mm NATO / .223 Remington
• Type: Bolt Assembly
• Included Components: Extractor
• Testing: High-Pressure Tested, Magnetic Particle Inspected
• Coating: Nanoweapon Finish
• Compatibility: AR-15 Platform