American Handgunner May/June 1977

HECKLER & KOCH'S4 CALIBER VERSATILITYBy GEORGE C. NONEack in the late 1960s the German firm of Heckler & KochB (Oberndorf am Neckar) introduced a new pocket-size,autoloading pistol of startling sophistication and modernity. Itpossessed many features not previously seen in such guns, someof them confusing from the viewpoints of both operation andfunctioning.Probably the most outstanding feature that confronted the potentialbuyer directly was the multiplicity of calibers one couldhave in a single gun by simply interchanging barrels and magazines.The HK-4, as it was designated, offered few-momentsinterchange between .22 LR, .25 ACP, .32 ACP, and .380 ACP.Of course, those are US. cartridge names, and H&K used thecorresponding metric designations of 6.35mm, 7.65mm, and9mmK for the center-fire numbers.Initially the HK-4 was sold singly in any one caliber, or as acased set containing the parts to accommodate all four cartridges.Harrington & Richardson handled distribution at first,but as the restrictions of GCA'68 took hold, and as H&R policieschanged, the HK-4 was dropped from the line. EventuallySecurity Arms Company (933 N. Kenmore St., Suite 218, Arlington,VA. 22201), which was already importing and distributingother H&K products, took over the HK-4 and now distributesit to the trade as the Heckler & Koch Company.Early HK-4s possessed a very heavy," irregular, and rough double-actionpull, but this has since been corrected to a large degree.Our sample gun, and others I've examined show considerableimprovement in this area, though still not as nice as someother designs. This seems odd inasmuch as H&K's big, P9,9mm pistol has an unusually soft and smooth DA pull.Early HK-4s contained, in .380 caliber, an unusual featurewhich I could never understand. The chamber contained longitudinalflutes of sharp-edged, rectangular section. These fluteswere deepest in their center, flattening out to nothing at eitherend. The flutes were clearly imprinted upon fired cases, andsome cases would split longitudinally along the flute edges. Thiswas likely an attempt to slow opening of the breech; it probablydid, to some extent, but that was not needed in the low-pressure.380 loading. The only result of the flutes was ruining the casesfor reloading, and excessive fouling of the chamber when casessplit. Presence of the flutes did not interfere with functioning;all such guns I fired were quite reliable.AMERICAN HANDQUNNER MAY/JUNE 1977