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

New Taurus Judge 1
New Taurus Judge 1

Gun of the Week: The New Taurus Judge

For 2026, Taurus USA took a fresh look at one of its most popular platforms, the Judge revolver, and updated it with a new feature set while retaining the versatility that made it popular in the first place.

The Armed Citizen® Sept. 18, 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.

This Maryland County Moved to Disarm Jews and Others in the Face of Evil

Even given the unconscionable history of gun control, the law banning concealed carry in and within 100 yards of houses of worship and other public assemblies in Montgomery County, Md., is particularly disturbing.

Review: Ruger American Gen II Patrol

Ruger's American rifle line represents a good balance between cost and performance, and the latest generation offers many welcome upgrades, as seen on this Gen II Patrol model in 5.56 NATO.

SOG Knives Celebrates 40 Years in Business

SOG Knives, which was established by Spencer Frazer in 1986, is celebrating its 40th anniversary in 2026.

The History of Repeating Arms Gun-Control Groups Don’t Want the Courts to Know

This episode of NRA’s The Armed Citizen Podcast refutes one of the biggest false claims gun-control groups and the politicians they support repeat ad nauseam by asserting that the Founding Fathers could not have imagined the AR-15.

Interests



Get the best of American Rifleman delivered to your inbox.