HK USP optic ready slide kit

Slated for release in Q2 2027, DeFender Automatics Co is pleased to announce the launch of our new Heckler and Koch optic ready slides for all hammer fired models, lengths, and calibers. 

DeFender Automatics Co lead engineer started with a blank sheet design approach for making the hammer fired HK slides optic ready. The goal was to take the existing HK pistol line up and bring it into the current century by offering multiple optic foot prints for the platform, while retaining as much Heckler and Koch parts interchangeably, reliability, durability, and manufacturing methods as the OEM itself. 

The biggest hurdle to adapting optics to the HK hammer fired pistol line is the firing pin block design, location, and position. To sink an optic low into the slide, the cut for the optic housing will pierce the firing pin block tunnel, and the spring will no longer have space to compress, and will no longer be captive. This requires that the internal portion of the slides, from the ejection port back to the hammer pocket be completely redesigned to fix this issue. 

The CEO of HKUSA went on record saying the costs to engineer the USP to accept an optic would exceed 4 million dollars. DeFender Automatics solved this problem by moving the spring laterally and elongating the firing pin block itself to accommodate the factory spring next to the block, instead of on top of it. This allows us to sink an optic low into the slide where the top of the slide and the bottom of the glass are in parallel.

We start from a raw steel forged blank just like HK does, and then modify the OEM cutting paths to delete the weight reduction channels, and create our firing pin block tunnel. The final steps are to cut the slide for the footprint desired (we currently offer Aimpoint COA, but have RMR, and ACRO footprints created) heat treat, and nitride coat the slide. 

DeFender Automatics Co HK optic ready slide kits take all factory HK slide parts except for:

Firing pin block

Roll pins

Iron sights

The optic slide kit includes the slide itself with optic cut for an Aimpoint COA, 2 shortened roll pins, COA front and rear iron sights and related hardware, and our proprietary firing pin block.

The DeFender Automatics Co HK optic ready slide kit reuses the following OEM HK slide parts:

Barrel

Recoil assembly 

Firing pin

Firing pin spring

Extractor

Extractor spring 

Firing pin block spring

Release of HK USP 9mm full size and compact optic ready slides for Aimpoint COA scheduled for sale in April 2027, with additional footprints to follow. 

We have completed modeling and engineering of the following HK pistols with COA, RMR and ACRO footprints:

9mm USP/full/tactical/Expert/compact

.45 USP/full/tactical/Expert/compact

.45 MK23

9mm P2000/sk

9mm P30/L/sk

Our plan is to eventually offer every model, length, and caliber of hammer fired HK pistol with an optic ready kit. Soon to be undergoing R&D will be the HK45 and HK45c, followed by the above models in .40cal.