Heckler & Koch: The Gray Room, Part I

by
posted on July 15, 2020
** 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. **
Watch our American Rifleman TV video above to learn about Heckler & Koch’s Gray Room and the designs that established the German-based firearm manufacturer.

Man standing with hands crossed in gray room with guns on walls.

Residing in Ashburn, Va., at the U.S. home of Heckler & Koch (H&K) is The Gray Room, a hidden gem brimming with prototypes and rare examples of H&K’s manufacturing expertise. Rooted in Oberndorf, Germany, H&K has built a worldwide reputation for its design and manufacturing capability.

Photographs of the three men who founded Heckler & Koch firearms company.

Edmund Heckler, Theodor Koch and Alex Seidel, all former Mauser engineers, started in the late 1940s what would become today’s Heckler & Koch. The newly-formed Germany engineering firm quickly morphed from a manufacturer of bicycles, machine tools and sewing machine parts to a firearm builder following an official West German request to product a new rifle for its army's infantry.

Cutaway view drawing of Heckler & Koch's roller-delayed mechanism.

What the Bundeswehr received from the fledgling company is known as the G3, a semi-automatic rifle with Spanish CETME roots that operates via short-recoil operation by way of a roller-locking mechanism. This new and innovative mechanism paved the way for H&K and the success it has earned over its 70+ years of manufacturing history.

Parts diagram for a G3 rifle.

The roller-delayed blowback system was the centerpiece of H&K shoulder-fired small arms production for almost 40 years. During the mid-1960s, production tapered for the G3, which led to the production of the MP5 submachine gun that fired the 9 mm Luger cartridge. The select-fire MP5 pistol is still in use today and commercial, semi-automatic variants are also available.

MP5N cutaway mounted on a gray wall.

As time advanced into the 1970s, H&K was tasked to design a replacement for its previous G3 design. The order was to create a firearm capable of firing caseless ammunition. The result became known to be the G11.

G11 rifle with helmet and ammunition on white background.

Creating the G11 weapon system was a joint effort between H&K, Dynamit Nobel and Hensoldt. Dynamit Nobel supplied the caseless ammunition, and Hensoldt engineered an integrated optic, which doubled as a carry handle. The result was a shoulder-fired arm that featured an ultra-high cyclic rate due to the advanced ammunition design.

Brochure for the G11 rifle and ammunition.

Technical issues of the G11 system slowed development, and the design faded as East and West Germany reunited in the early '90s. The outdated and large G3 rifle system needed refinement and H&K came to market with its G36 to assist the German army with a lightweight firearm that allows its operator to carry more ammunition.

G36 rifle made of clear plastic to view internal mechanisms.

This lightweight gas-operated G36 rifle chambers the smaller and effective 5.56x45 mm NATO cartridge and employs use of a short-recoil gas-operating system that does away with the legacy roller-delayed bolt design in favor of a rotary-bolt locking system.

SP5K pistol close-up view.

Follow along with American Rifleman’s Joe Kurtenbach and his visit with Heckler & Koch’s Grey Room to learn more about the company’s manufacturing history.

Latest

FK Brno PSD-C
FK Brno PSD-C

Review: FK Brno PSD-C

Manufacturers have achieved excellent results with small-caliber bottleneck designs, as evidenced by cartridges such as the .357 SIG and 5.7x28 mm. The .30-caliber 7.5 FK continues this legacy and is now chambered in the FK Brno PSD-C.

Firearm Industry Celebrates America's 250th With More Commemorative Options

For the entirety of 2026, we're celebrating America's 250th anniversary, and the firearm industry continues to roll out commemorative products to mark the occasion.

Maxed Out: Derya's New MAX Shotgun

The Derya Arms MAX is a new semi-auto shotgun designed for serious competitive shooters that is made entirely in the USA.

Breaking Through the "Bulletproof Bubble"

The "Bulletproof Bubble" is one of the most frustrating things a shooter can experience, because it doesn't make any sense. Every round seems to land all around the exact center of your point of aim instead of in it.

Sharpen Your Shooting Skills: Prairie Dogs

Reactive targets, such as prairie dogs, offer many lessons about one’s long-range abilities.

The Armed Citizen® Aug. 7, 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.