Griffin Armament High Endurance Dual Purpose (HEDP) Barrel M4A1 Contour 5R Rifling Stainless Steel Nitride with Low Profile Gas Block

The Griffin Armament HEDP™ Barrels provide High Endurance Dual Purpose functionality- offering high durability and precision accuracy. Nitrided 416R stainless steel provides the highest possible hardness and longest throat life available with match grade bore dimensions and bore finish. HEDP barrel bores are hand-lapped, ensuring batch to batch consistency and accuracy. TRUE-BORE™ concentric suppressor grade threads provide an optimized thread interface for your silencer regardless of brand or model. M4 feed ramps and chambers are polished prior to nitriding for smooth reliable feeding, chambering, and extraction. Gas ports were carefully engineered to provide reliable function suppressed and unsuppressed with both supersonic and subsonic ammunition. A medium contour diameter between the chamber and gas block for minimal POI shift with suppressors and maximum accuracy and durability while maintaining field weight. The included 416R Low profile Griffin Armament Primo Gas Block™ offers unmatched value in the interest of increased customer satisfaction. 

5R rifling is believed by many to be superior to conventional rifling, reducing bullet deformation, and barrel fouling, affording more consistent accuracy, reduction of wear (greater life), and greater ease of cleaning.  5R rifling was used in the legendary Army M24 Sniper Weapon System (SWS) and those rifles were found to meet or exceed accuracy requirements at over 20,000 rounds fired.  

The PRIMO Gas Block can be pinned by a trained gunsmith. Alternatively end users can quickly mount their block with the included set screws. Proficient builders should use a carbide tipped 1/8″ drill bit to complete the pin hole prior to pressing the included splined pin. (splined pin installation is optional)

Features

• 416R SS barrel manufactured from stress relieved certified barrel steel
• Black nitrided for extended service life
• Magnetic particle inspected
• Button rifled
• 5R rifling offering less constriction on the bullet
• .750″ gas block journal
• Air gauged and hand-lapped bore
• Polished chamber and M4 feed ramps
• TRU-BORE™ suppressor quality threads
• Suppressor optimized gas ports
• Included 416R Low Profile PRIMO Gas Block™