Home / Services HK416 MR556 / HK 416A5 Extended Castle Nut View cart “HK Style 416A5 Rear Sling Swivel Back Plate” has been added to your cart. HK 416A5 Extended Castle Nut$2400 SKU: CSTLNUTA5 Categories: 416 417 G28 M110, Services HK416 MR556 Tags: 416, 416A5, MR556 Product ID: 4355 HK 416A5/A7/F extended castle nut, steel These are perfect for the 416, 416A5, 416A7 and any other compatible platform. Steel Black Excellent fit and finish, just like factory Product is out of stock Notify me when this product is back. Please enter a valid email! Subscribe Description Additional information Description HK 416A5/A7/F extended castle nut, steel These are perfect for the 416, 416A5, 416A7 and any other compatible platform. Steel Black Excellent fit and finish, just like factory Additional information Weight 5 oz Dimensions 2 × 1 × 1 in Related products Out of stock HK 416/M27 Style Bayonet Lug $4900 Out of stock HK 416C Style Short Quad Rail Foregrip Handguard Black $17900 Out of stock HK 416D Style Standard Quad Rail Foregrip Handguard Black $14900 HK Style 416A5 Rear Sling Swivel Back Plate $1900