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
-
HK 416, R556 Castle Nut - A5 Style - Extended
HKP HK Parts
$39.95HK 416, MR556 A5 Style Extended Length Castle Nut Unlike the factory German A5 castle, our A5 extended buffer tube castle nut is compatible with both mil-spec & commercial buffer tubes. Crafted from ordnance grade steel and nitrided for a...$39.95 -
HK Picatinny Rail For HK Receivers - 15 Slot
HKP HK Parts
$59.95HKP Picatinny Rail For HK Receivers - 15 Slot Mil-Spec all steel CNC'ed picatinny rail in the white, relief cut to fit flush and low profile on HK receivers. The most solid and consistent mounting platform made for mounting scopes and optics to HK builds...$59.95 -
Picatinny Rail for HK Receivers - 13 Slot
HKP HK Parts
$52.95HKP Picatinny Rail For HK Receivers - 13 Slot Mil-Spec all steel CNC'ed picatinny rail in the white, relief cut to fit flush and low profile on HK receivers. The most solid and consistent mounting platform made for mounting scopes and optics to HK builds...$52.95 -
HK UMP, USC 9mm / .40 S&W / .45 ACP Enhanced Top Receiver Rail
HKP HK Parts
$49.95HK USC & UMP Top Receiver Rail With Hardware - US Made The extended length allows the use of all optics that fit on a Picatinny rail. This unit has a contoured, no-snag design for ease of use and a beautiful fit. Made from billet machined aluminum...$49.95 -
Out Of Stock
HK MP5, MP5K Contact Piece for Paddle Mag Release - 9mm - US
HKP HK Parts
$15.95HK MP5, MP5K 9mm Contact Piece - USA Factory correct US manufactured MP5, MP5K 9mm Contact Piece for Paddle magazine release. Each part was made using the same material and manufacturing methods used on the German HK latest production parts. Hard to find...$15.95 -
HK MP5, G3, PTR, HK93 Push Button for Magazine Catch
H&K Heckler & Koch
$8.95Push Button For Magazine Catch Compatible With: G3 91 MP5 MP5K SP5K-PDW (For SP5K's not equipped with the paddle release, purchase this kit) 94 93 33 PTR, Clones, ETC.$8.95 -
HK MP5, HK94 Complete Weldment Set For Receiver Flat
HKP HK Parts
$59.95HKP MP5/HK94 Complete Weldment Set For Receiver Flat This is the finest, most correct weldment set for your HK MP5, 94 project available. Each Weldment Kit Contains: 1x Semi Auto Shelf Hanger Block 1x Rear stock bushing 1x Scope mounting piece 1x...$59.95 -
Out Of StockOn Sale
HK Style Jig Set - Flat Bending - Billeted - All Steel
HKP HK Parts
Now: $449.95Was: $599.95Flat Bending Jig Set For All HK Style Flats - Billeted - All Steel All steel billeted universal flat bending jig for all HK receiver flats including PTR .308 flats and the PTR/LSC flats. Each bending jig comes complete with all the pieces you need for...Now: $449.95Was: $599.95 -
Out Of Stock
HK MP5, MP5K 9mm Anti-Rattle Roller Tipped Paddle Magazine Release
HKP HK Parts
$29.47HK MP5, MP5K 9mm Anti-Rattle Roller Tipped Paddle Magazine Release Latest generation paddle mag release for all 9mm MP5, MP5K style builds. Made to the latest German specs, materials, and design. Compatible With: MP5, 94 MP5K, SP89, SP5K Other...$29.47 -
HK MP5 Receiver Flat with Weldment Set - 9mm
HKP HK Parts
$219.95HKP HK MP5 9mm Receiver Flat with Weldment Set New MP5 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...$219.95 -
HK416, MR556 Ejection Port Cover
H&K Heckler & Koch
$54.95H&K HK MR556/416 Ejection Port Cover HK manufactured newer polymer style cover assembly found on the latest HK 416 & MR556. This item can also be used on other AR15-style projects to enhance the project with the finest ejection port cover...$54.95 -
HK MP5 Receiver Flat with Weldment Set
PTR
$294.95MP5 9mm Receiver Flat With Complete Weldment & Rivet Set - PTR/LSC Several years ago PTR bought out LSC and now owns the tooling and dyes for the LSC 9mm flats. These elusive flats have been hard to find and are now available for the first time here...$294.95