By Dan Shea
We at Small Arms Defense Journal have always tried to have a bit of reference material in each issue, something you can save for later identification. In this issue, we’re covering Heckler and Koch’s original 5.56x45mm select fire rifle—the HK33 series. It’s comprised of the HK33 rifle, the short-barrel HK33K, the semi-auto HK93, the HK33 SG1 sniper variant, the HK53 “Submachine gun,” and the various HK13 designs.
The weapon system was meant to be the roller locking answer to the 5.56mm M16 system and was successfully sold in many countries.
In 1965-66, HK produced a promotional catalog showing all of its products. At this time, the MP5 was called the HK54. In addition to the, then, unheard of HK25 belt fed .50 BMG which looked like an HK21 with a belt of .50 hanging from it, there were HK32 variants offered in 7.62x39mm and a number of 5.56mm variations: HK33, HK33K, and the HK13. The catalog lists the HK33 with a 20-round magazine, the HK33K with a 40-round magazine, and the HK13 with a 100-round magazine. We’ve never seen this offset “drum” type HK 5.56mm in the wild. Another item of note: the HK13 was a heavy barrel gun, but the original did not have a quick-change feature; the barrels of later HK13s could be changed like the HK21/23 series belt feds.
The HK magazines are of the box shape type, curved to match the taper of the 5.56mm case, and are double column, and present to the bolt from both columns. A magazine such as a Sten (not shown) is double column and feeds from a single central position—both columns must move the rounds to the center. A magazine that feeds from dual presentation, like the HK magazines and the M16 magazine, has less resistance in feeding, and the bolt must be designed to drive the cartridge to the feed ramp from both columns. It’s a successful and reliable design.
A closer look at the original and the 1994 compliant LE markings for U.S. import. 5.56x45mm is engraved along the edge.
Over the course of 40 years, myself along with William Vallerand, Herbie Woodend, Bob Faris, and others, designed an identification system that we referred to as the “Vallerand Magazine ID System.” There were about 4000 magazines for machine guns and rifles that we photographed and measured, hoping to someday put this into a forensic system. A description of the system is available on www.smallarmsreview.com. Just search the Archives section for “Vallerand” to find a link. If you have input on this, please let us know.