The Heckler & Koch Receiver Extension Nut (H&K part no. 50233165) is a genuine factory part built for the HK416 platform, fitted to the MR556A1. It threads onto the receiver extension (buffer tube) and clamps it to the lower receiver, so a stripped or damaged nut is a direct cause of a loose, wobbling stock assembly.

Key Specifications

• built for the HK416 platform specifically fitted to the MR556A1.
• secures the receiver extension to the lower eliminating play in the stock assembly.
• factory H&K replacement part matching original thread pitch and fit.

Frequently Asked Questions

What rifle platform is this for? It is a factory-correct receiver extension nut for the HK416 platform, fitted to the MR556A1.

What does this nut do? It clamps the receiver extension (buffer tube) to the lower receiver, eliminating stock play.

Buy the HK416/MR556A1 Receiver Extension Nut

Eliminate stock wobble with the current factory H&K receiver extension nut. Browse more of our rifle parts selection and order from our Lubbock, Texas gun shop.