H&K 51000385 MR556 Upper Receiver Kit 5.56mm AR15/M16/M4 A4 Features
Shop Heckler & Koch ProductsThis item is currently out of stock. Enter your email below and we'll notify you when it's available!
We'll only use your email to notify you about this product.
HK MR556 Upper Receiver Kit 5.56mm - Model 51000385 - UPC: 642230270220
The HK MR556 Upper Receiver Kit is designed to retrofit Mil-Spec 5.56mm AR-style rifles with HK's advanced piston and pusher rod system. This system replaces the traditional gas tube, significantly reducing malfunctions by preventing hot carbon fouling and waste gases from entering the receiver. This technology is a key feature of the HK416, trusted by elite military and law enforcement units. The kit includes a complete upper receiver/barrel assembly and ships in an HK soft case.
Specs:
Technical Specifications
| Caliber | 223 REM | 5.56 NATO |
|---|---|
| Barrel Length | 11.00" |
| Action Type | Piston |
| Finish | Matte Black |
| Weight | 8.8 lbs |
| Twist Rate | 1-in-7 |
| Manufacturer | Heckler & Koch |
| Model | 51000385 |
| SKU | Ba1188663 |
| UPC | 642230270220 |
| Color | Black |
| Availability | Out of Stock |
Customer Reviews
No reviews yet. Be the first to review this product!
Shipping & Returns
Shipping Information
- Ships via major carriers with tracking
- Tracking information provided for all orders
- Shipping costs calculated at checkout based on weight and destination
Return Policy
- 30-day return policy on accessories and non-firearms
- Items must be unused and in original packaging
- Contact us for return authorization before shipping items back
- Original shipping costs are non-refundable
Questions?
Contact us at 7048882913 or submit a question for assistance with shipping or returns.
Get Your Exclusive Price
Enter your email and we'll instantly send you our best price for this item.
Purchase now at the listed MAP price
What is MAP Pricing?
MAP stands for Minimum Advertised Price. It's a policy set by manufacturers that limits how low retailers can advertise their prices.
The good news? We can often sell below MAP - we just can't show that price publicly. When you request a price by email or add to cart, you'll see our actual (often lower) price.
This isn't a trick - it's how we stay compliant while still offering you the best deals possible.
