AB Arms AR-15 Pro Bolt Assembly is built to Mil-Spec dimensions. The Nickel Boron coated bolt needs virtually no lube during use. The Manganese Phosphate coated extractor has a surface finish that provides superior extraction during firing.

These bolt assemblies are ready to drop into your bolt carrier group. These Bolts are specially made on high end Swiss machinery to have exacting tolerances and surface finish. AB Arms is known by rifle manufacturers for manufacturing one of the finest quality bolts and extractors available.

Features and Specifications:
Manufacturer Number: ABA5.56B
223 REM/5.56 NATO/.300 AAC Bolt
Carpenter 158 Steel
Heat treated per Mil-Spec Requirements
Shot Peened per Mil-Spec Requirements
MPI Tested Material
Nickel Boron Coated
Extractor
Aircraft Quality E4140 Steel
Heat treated per Mil-Spec Requirements
Shot Peened per Mil-Spec Requirements
Manganese Phosphate Coated per Mil-Spec Requirements

Made in the USA!