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.
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Out Of Stock
HK416, MR556 Ejection Port Cover Assembly
H&K Heckler & Koch
$89.95HK German HK 416, MR556 Ejection Port Cover Door Assembly Complete This is the newer polymer style cover found on the latest HK 416 and MR556's. This is the complete ejection port door assembly needed on all AR15 or MR556/HK416 models. Can also be used...HKP-16951$89.95 -
On Sale
HK MP5F Receiver Flat - Alternate Holes
HKP HK Parts
Now: $99.95Was: $125.95HKP HK MP5F 9mm Flat - Alternate Holes MP5 receiver flat crafted by the original German tool and die maker of the LSC receiver flat using factory original German prints and specifications. This receiver features alternate holes for the correct MP5F or...HKP-21551Now: $99.95Was: $125.95 -
On Sale
Picatinny Rail for HK Receivers - 15 Slot
DTAC Dakota Tactical
Now: $59.95Was: $74.95Dakota Tactical Picatinny Rail To Weld To The Receiver 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...HKP-17819Now: $59.95Was: $74.95 -
On Sale
HK MP5K, SP89 Receiver Flat with Weldment Set
HKP HK Parts
Now: $191.95Was: $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-20882Now: $191.95Was: $239.95 -
On Sale
HK MP5, HK94, MP5K, SP5K Tac Latch
Other
Now: $58.95Was: $69.95New Tac Latch (latest Generation) Paddle Style Magazine Release For The HK94, SP89, HK SP5K Family of Firearms HK's were designed to have a quick one-handed release capability for the magazine (paddle mag release). However, the semi-auto...HKP-02792Now: $58.95Was: $69.95 -
Out Of Stock
HK416, MR556 Piston Guide - Threaded - Upper Receiver
H&K Heckler & Koch
$19.95Heckler and Koch Upper Receiver Threaded Piston Guide for HK MR556 and HK416 Compatible With: HK416, MR556 M27HKP-02640$19.95 -
Out Of Stock
HK21, HK11 Trunnion
RCM
$274.95RCM HK21 Trunnion When RCM set out to make a replacement trunnion for the venerable HK21, they started the process by putting a factory unit through rigorous destructive metal testing. The end-product: a US-made trunnion blending the proper...HKP-21609$274.95 -
Out Of Stock
HK416, MR556 Magazine Release Button
H&K Heckler & Koch
$16.95Heckler and Koch Magazine Release Button for HK416 and HK MR556 New HK German Manufacture. Compatible With: HK416, MR556 AR15, M4, M16 firearmsHKP-02656$16.95 -
HK416, MR556 Ejector Port Cover Pin
H&K Heckler & Koch
$19.95Heckler and Koch Ejector Port Cover Axle Pin for HK416 and HK MR556 Compatible With: HK416, MR556HKP-02661$19.95 -
HK45, P30, P30L, P30SK Magazine Release
H&K Heckler & Koch
$15.95Heckler and Koch Magazine Release for HK45 and HK P30 Compatible With: HK45 HK45 Tactical HK P30, P30S, P30L, P30SK Please Note: This part will not fit pistols other than the ones listed above.HKP-01809$15.95 -
HK417, MR762, G28 Buffer Tube Castle Nut - Extended
H&K Heckler & Koch
$85.95Heckler and Koch Buffer Tube Castle Nut for HK G28, HK417 and HK MR762 New HK German G28 castle nut for the HK MR762, HK417, and G28 models. Black in color. This is the proper part for use with the G28 buffer tube and stock upgrades...HKP-16763$85.95 -
HK416A5 Stripped Upper Receiver
H&K Heckler & Koch
$489.99HK 416A5 - Stripped Upper Receiver This is the factory correct receiver for a true 416 build as it features the M16 relief cut in the bottom, rear portion of the receiver (shown in last pricture). Compatible With: HK 416 HK MR223 HK MR556 Need a...HKP-18786$489.99