HK UPPER RECEIVER KIT MR556A4 16.5”. 5″ – HK 51000384 UPPER RECEIVER KIT MR556A4 16.5″
Rock River Arms Completed Upper Receiver National Match A4 .223/5.56mm 20 Inch Barrel Competition Profile 1-8 Twist 1/2-28 Thread Free-Float Handguard
Original price was: $865.00.$709.99Current price is: $709.99. 
Stag Arms AR-15 Lower Receiver Parts Kit w/ Selector Left-Handed Selector
Original price was: $74.99.$64.99Current price is: $64.99.
HK UPPER RECEIVER KIT MR556A4 16.5”
Original price was: $2,499.00.$2,179.00Current price is: $2,179.00.
Additional information
| Brand | Heckler & Koch |
|---|---|
| Merchant | Optics Planet |
