HK Mod 4 .22 LR Compact Pistol, 3.35 in Fixed Barrel, DA/SA, German-Made (October 1971), Import-Marked, Includes .32 ACP Barrel Assembly
German-made in October 1971, this HK Mod 4 represents Heckler & Koch’s first production handgun and the company’s innovative modular, four-caliber design. It is currently configured in .22 LR and includes a separate 7.65 mm Browning (.32 ACP) barrel assembly with recoil spring, enhancing its versatility. German proof marks and the HK Inc. Arlington, VA 22201 import marking are present, adding clear provenance for collectors.
Condition
Overall Condition: Very good condition, showing only light, superficial signs of prior handling or use.
Bore Overall Condition: Excellent - Clean, mirror finish, no signs of wear.
Bore Rifling: Excellent Rifling - Sharp lands and grooves.
Specific Condition Notes: The pistol shows a few faint handling marks and small superficial blemishes. The bore is bright and reflective.
What’s Included
- No case included
- Manual
- 2 magazines
- Separate 7.65 mm Browning (.32 ACP) barrel assembly with recoil spring
The HK 4 was engineered as a compact, modular straight-blowback pistol capable of running four calibers (.22 LR, .25 ACP, .32 ACP, .380 ACP). Production totaled about 38,000 pistols, with early U.S. distribution handled first by H&R and later by HK Inc. This example carries German proof/test marks and the HK Inc. Arlington, VA 22201 import mark, confirming its period import history.
It is currently set up in .22 LR with a 3.35 inch fixed barrel and a 10+1 capacity. This sale also includes a 7.65 mm Browning (.32 ACP) barrel and recoil spring assembly, allowing the owner to convert it from rimfire to centerfire in keeping with the HK 4’s modular concept.
Mechanically, the pistol uses a DA/SA trigger and a straight-blowback system with the recoil spring encircling the fixed barrel. A barrel lock lever inside the trigger guard facilitates barrel changes. The design incorporates a reversible dual-channel breech plate for rimfire/centerfire operation, along with manual and internal safeties.
Construction details include an aluminum-alloy frame with a hard-anodized finish and a blued/black slide featuring an ejection-port insert. The external, partially shrouded hammer, fixed blade front sight, and fixed notch rear sight support the compact pistol’s straightforward operating profile. Black checkered plastic grips with the HK logo complete the classic presentation.
As HK’s first production handgun and a hallmark of the company’s modular engineering approach, the HK 4 holds a distinct place among German pistols of the 1970s. The included .32 ACP barrel assembly adds practical flexibility while preserving the model’s original multi-caliber intent.