Receivers / Flats / Uppers
Explore our premier selection of HK receivers, flats, and uppers at HKParts, perfect for building or upgrading your Heckler & Koch firearms. Our products feature precision-engineered MP5 receiver flats, HK 416 complete upper assemblies, and a wide range of custom options designed for tactical and precision shooting. Whether you are customizing an MP5, upgrading an HK416, or constructing a new firearm, our high-quality components provide unparalleled reliability and performance.
- Product
- Qty in Cart
- Quantity
- Price
- Subtotal
-
HK416, MR556 Buffer Tube Wrench
HKP HK Parts
$29.95HK MR556 & HK416 Buffer Tube Wrench The perfect metric wrench to remove and install the MR556 & HK 416 castle nuts on the buffer tube. A perfect addition to have on hand for OTB or other HK buffer tube upgrades, etc. Made from all steel, heat...HKP-17124$29.95 -
Out Of Stock
HK SP5K 9mm Drop In Paddle Mag Release Upgrade Kit
H&K Heckler & Koch
$129.95HKP HK Parts and Heckler and Koch Anti-Rattle Roller Tipped Paddle Magazine Release Kit No modifications, no refinishing...complete drop-in kit included New HK German and USA made paddle mag release kit for the HK SP5K. This kit will allow any...HKP-18082$129.95 -
HK SL8, G36 Magazine Release Axle Pin
GSG9
$10.95GSG9 Magazine Release Axle - USA made for HK G36 and HK SL8 Mag release axle for all G36 and SL8 models. A must-have spare part. Made in the USA. Compatible With: G36 G36K SL8 Other custom G36 type buildsHKP-18255$10.95 -
HK416, MR556 Magazine Catch
H&K Heckler & Koch
$61.95Heckler and Koch Magazine Catch for HK416 and HK MR556 New HK German manufacture magazine catch for the HK 416 and MR556 family of firearms. Compatible With: HK416, MR556HKP-15458$61.95 -
HK416, MR556, HK417, MR762 Forward Assist Plunger Spring
H&K Heckler & Koch
$5.95Heckler and Koch's Forward Assist Plunger Spring for HK416, MR556, HK417, MR762 New HK German manufacture. Compatible With: HK416, MR556 HK417, MR762 HK G28 HK M27HKP-02537$5.95 -
Out Of Stock
HK416, MR556 Receiver End Plate
H&K Heckler & Koch
$24.95HK 416, MR556 End Plate For Receiver & Buffer Tube New HK German manufacture. Compatible With: HK MR556 & HK 416 upper receiver/buffer tubesHKP-16603$24.95 -
Out Of Stock
HK416, MR556 Takedown Pin - Front - A1 Style
H&K Heckler & Koch
$64.95H&K HK MR556 Front Lower Receiver Locking Pin With Spring Loaded Detent This part is the front (large) takedown pin with ball detent and locking mechanism installed. The idea behind this type of system is to decrease the movement of the upper and...HKP-02663$64.95 -
HK MR556 Incomplete Upper Receiver
H&K Heckler & Koch
$440.95HK German Stripped HK MR556 Upper Receiver New factory German incomplete and unmarked MR556 upper receiver. Compatible With: HK MR556 HK MR223 HK 416 Do you need a matching lower for your build? STS416 A5 LOWER - Specialized Tactical...HKP-02615$440.95 -
HK MP5 Receiver Flat- 9mm
LSC
$239.95MP5 Receiver Flat - PTR/LSC New PTR 9mm Receiver Flat made on the original LSC tooling. This flat is considered by many to be the most sought-after HK flat available on the market and perfect for that HK custom build. This item is not considered an FFL...HKP-01431$239.95 -
HK416, MR556, MR762 Forward Assist Assembly, Complete
H&K Heckler & Koch
$74.95H&K Heckler and Koch Forward Assist Assembly for HK416, HK MR556, and HK MR762 H&K Germany factory HK MR556 and HK416 forward assist assembly complete. Compatible With: HK 416, MR556 HK MR762HKP-16528$74.95 -
HK MP5K, SP89 Receiver Flat with Weldment Set
HKP HK Parts
$239.95HKP - MP5K, SP89 Receiver Flat With Weldment Set New MP5K receiver flat and weldment set combined for the best complete build option on the market. Made by the original German tool and die maker of the LSC receiver flat utilizing factory original German...HKP-20882$239.95 -
Out Of Stock
HK SP5 Case Deflector - 9mm, 10mm, .40 S&W
H&K Heckler & Koch
$49.95Heckler and Koch Case Deflector for 9mm, 10mm, and .40 S&W HK SP5 Factory HK case deflector for the SP5 platform chambered in 9mm, 10mm, and .40 S&W. Compatible With: SP5HKP-02170$49.95