This kit includes a complete upper receiver/barrel assembly, allowing Mil-Spec 5.56mm AR-style rifles to be retrofitted to HKs piston and pusher rod system. This system utilizes a piston and a pusher rod in place of the gas tube normally found in AR15/M16/M4-style rifles. This closed system virtually eliminates the malfunctions that are common in direct-impingement gas systems, since hot carbon fouling and waste gasses are not propelled into the receiver area to operate the action. This is the same key feature critical to the success of the HK416 used by elite military and law enforcement customers. Upper will ship in HK Soft case.
“Spikes SFT50M4 Flat Top Stripped Upper Multi-Caliber 7075-T6 Aluminum Black Anodized Receiver for M4 Platform” has been added to your cart. View cart
| Manufacturer | HK |
|---|---|
| Caliber | 5.56mm |
| Compatibility | |
| Model | |
| Platform | |
| Product Type |
Be the first to review “HK 51000385 MR556 Upper Receiver Kit 5.56mm for AR15/M16/M4” Cancel reply
You must be logged in to post a review.
Related products
-
Out of stockComplete Upper Receivers
Aero Precision APAR600201AC M4E1 Enhanced Receiver 5.56x45mm NATO 7075-T6 Aluminum Black Anodized Receiver for AR-15
$157.85Out of stock. Join the waitlist to be notified when this product becomes available. -
Out of stockComplete Upper Receivers
Spikes STU5435MLS Complete Upper 5.56x45mm NATO 16″ Black Phosphate/Midlength Barrel, 7075-T6 Aluminum Black Receiver, 12″ SAR3 Free-Floating Handguard for AR-15
$511.17Out of stock. Join the waitlist to be notified when this product becomes available. -
Out of stockComplete Upper Receivers
Chiappa Firearms 500095 M4-22 Gen II Pro Upper 22 LR 16″ Steel Barrel, Matte Black Polymer Receiver, 11.80″ Quad Picatinny Rail For Use With Mil-Spec Lower Receivers Includes 2 28rd Mags
$274.34Out of stock. Join the waitlist to be notified when this product becomes available. -
Out of stockComplete Upper Receivers
Primary Weapons M116UA0B MK1 Mod 1-M Upper 223 Wylde 16.10″ Chrome-Lined 4140 Steel Barrel w/Removeable Muzzle Device, 7075-T6 Anodized Aluminum Receiver, 15.05″ M-LOK Handguard For AR-15
$850.03Out of stock. Join the waitlist to be notified when this product becomes available. -
Out of stockComplete Upper Receivers
Aero Precision APAR501801AC Assembled Receiver Multi-Caliber 7075-T6 Aluminum Flat Dark Earth Cerakote Receiver for AR-15
$104.96Out of stock. Join the waitlist to be notified when this product becomes available.



Reviews
There are no reviews yet.