WHAT DOES HK-416D MEAN?

The HK416 is commonly regarded as an improvement in excess of the AR-fifteen/M16 System as a consequence of its cleaner quick-stroke gas piston program, enhanced accuracy with a free of charge-floating barrel, and ambidextrous controls. [forty nine] The MR556A1 lets the upper receiver attach to any M16/M4/AR-15 relatives lower receiver, as the rec