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
-
On Sale
HK G36 Backplate
H&K Heckler & Koch
Now: $85.49Was: $94.99HK G36 Backplate With Recoil Buffer This is a great spare or replacement to have on hand. These are also required for those that are doing the SL8-G36 conversions provided by Tommy Bostic & Chopstix Kid.Now: $85.49Was: $94.99 -
On Sale
HK416, HK417, MR556, MR762 Forward Assist Plunger Spring
H&K Heckler & Koch
Now: $5.36Was: $5.95H&K HK MR556/MR762/416/417 Forward Assist Plunger Spring New HK German manufacture. Compatible With: HK MR556 HK 416 HK MR762 HK 417 HK G28 HK M27Now: $5.36Was: $5.95 -
On Sale
HK91, G3, HK33, HK53, HK93 Contact Piece for Paddle Mag Release
H&K Heckler & Koch
Now: $26.95Was: $29.95HK .223/556 & 308 Contact Piece For Paddle Magazine Release German HK manufacture. The contact piece is used in the magazine release assembly for the paddle mag release. Compatible With: HK 33, 53, 93 HK G3, 91, PTR91Now: $26.95Was: $29.95 -
On Sale
HK MP5 Receiver Flat - 9mm
HKP HK Parts
Now: $151.96Was: $189.95HKP HK MP5 9mm Receiver Flat New MP5 receiver flat made by the original German tool and die maker of the LSC receiver flat utilizing factory original German prints and specifications. The creator of our receiver flat has been regarded as the premier flat...Now: $151.96Was: $189.95 -
On Sale
HK MP5K, SP89 Receiver Flat with Weldment Set
HKP HK Parts
Now: $191.96Was: $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...Now: $191.96Was: $239.95 -
On Sale
HK416, MR556 Ejector Port Cover Pin
H&K Heckler & Koch
Now: $17.95Was: $19.95HK MR556 & 416 Ejector Port Cover Pin Compatible With: HK MR556 HK 416Now: $17.95Was: $19.95 -
HK Mil-Spec Buffer Tube Kit
HKP HK Parts
$42.95Mil-Spec Buffer Tube Kit Compatible With: HK MR556 & 416 AR-15 style platforms Includes: Made with T7 7075 aircraft-grade aluminum Made in the USA with a polished inside tube Mil-Spec triple hard coat Teflon anodized finish Each unit comes with a...$42.95 -
On Sale
HK MP5K 9mm Trunnion
HKP HK Parts
Now: $46.36Was: $57.95HK MP5K Trunnion - USA US made to exact factory HK specifications for the HK MP5K type builds. Machined completely from ordnance grade steel and heat treated to factory specs. These are the best USA made trunnions on the market. Machined to HK spec...Now: $46.36Was: $57.95 -
On Sale
HK G36 Backplate Complete w/ Recoil Assembly
USA
Now: $76.45Was: $84.95HK G36 Backplate Complete With Recoil Assembly New G36 Backplate with new G36/SL8 recoil buffer and recoil assembly. This assembly does include the recoil rod retaining screw. This is a great spare or replacement to have on hand. These are also required...Now: $76.45Was: $84.95 -
On Sale
HK MP5, MP5K Rear Sight Base - Billeted
HKP HK Parts
Now: $14.36Was: $17.95Billeted MP5, MP5K Rear Sight Base - Weldment All steel HK MP5, MP5K billeted rear sight base. The most correct MP5, MP5K rear sight base available. The only billeted factory correct sight base with the factory HK German side axis grooves. If you want...Now: $14.36Was: $17.95 -
On Sale
DTAC Picatinny Rail For HK Receivers - 13 Slot
DTAC Dakota Tactical
Now: $67.45Was: $74.95DTAC Picatinny Rail For HK Receivers - 13 Slot Mil-Spec all steel picatinny rail in the white, relief cut for HK receivers & made for mounting scopes and optics to HK builds. This unit easily welds to the top of your HK receiver. Compatible With: HK...Now: $67.45Was: $74.95 -
On Sale
HK416, MR556 Buffer Tube - Enhanced
H&K Heckler & Koch
Now: $179.95Was: $199.95FDE HK 416, MR556 OTB (over the beach) Buffer Tube, Receiver Extension - Commercial Genuine HK German manufactured 416 & MR556 latest generation, marine environment & over the beach buffer tube. Each commercial buffer tube has built in drainage...Now: $179.95Was: $199.95