Rifleman Q&A: A Convertible Semi-Automatic H&R Pistol?

by
posted on October 14, 2022
** When you buy products through the links on our site, we may earn a commission that supports NRA's mission to protect, preserve and defend the Second Amendment. **
HRHK4

Q. I recently acquired an unusual, compact, semi-automatic pistol. I don’t know much about it. The slide is marked “Harrington & Richardson, Inc. Worchester, Mass. USA, Made in Germany Mod. HK4 Cal. 380.” There is also a lion stamped between the dates 1871 and 1971. Can you tell me what I have?


A. It appears you have an HK4 .380 ACP pistol made by Heckler & Koch in Germany. This is a blowback-operated semi-automatic pistol based on the Mauser HSc design of the 1930s. They were chambered for .22 LR, .25 ACP, .32 ACP and .380 ACP cartridges. These calibers were easily converted by switching the barrels, recoil springs and magazines. The rimfire model could be changed by rotating the breechface. Conversion kits were available for all calibers. The barrel is 3” long, and the finish is blued. The molded plastic grips feature thumb rests. The pistol was sold from 1968 to 1973 as the Harrington & Richardson HK4 and is so marked. The HK4 was completely discontinued in 1984.

—Harry Hunter


This “Questions & Answers” was featured in the October 2009 issue of American Rifleman. At time of publication, "Questions & Answers" was compiled by Staff, Ballistics Editor William C. Davis, Jr., and Contributing Editors: David Andrews, Hugh C. Birnbaum, Bruce N. Canfield, O. Reid Coffield, Charles M. Fagg, Angus Laidlaw, Harry Hunter, Charles E. Petty, Jon R. Sundra, Jim Supica, John M. Taylor and John W. Treakle.

To subscribe to the magazine, visit the NRA membership page and select American Rifleman as your member magazine.

Latest

Springfield Echelon Pro 01
Springfield Echelon Pro 01

Going Pro: Springfield Armory's Echelon Pro Comp

Springfield Armory has expanded its Echelon line of handguns with several new Echelon Pro Comp offerings, bringing a number of what the company calls "performance-oriented enhancements" to the platform.

Steel Yourselves—Metal is Back

These days, it’s safe to say that injection-molded polymer of some sort is the most prevalent material from which to construct a pistol frame, but lately, that trend seems to be reversing. Metal is back.

NRA-ILA Names National Shooting Sports Foundation Official Partner of the 2026 NRA Gun Bus Battleground Tour

This sponsorship through NSSF’s Protect Liberty PAC puts the firearms industry trade association on the road through Election Day.

Ori-gun-i: The ZEV Technologies FDP Carbine

The American art of folding polymer and steel into a working firearm reaches what might be its zenith with the Zev Technologies/Magpul FDP.

Study Finds Correlation Between Firearm Training & Safe Gun Storage

In a survey of more than 1,000 firearm owners across the nation, researchers found that firearm training increases responsible gun storage at a dramatic rate.

The Armed Citizen® Oct. 12, 2026

Read today's "The Armed Citizen" entry for real stories of law-abiding citizens, past and present, who used their firearms to save lives.

Interests



Get the best of American Rifleman delivered to your inbox.