In May of this year, I got the rare opportunity to travel to Heckler & Koch’s headquarters in Ashburn, VA, to take a look at some of the experimental and prototype firearms they have located there in their famous “Grey Room”. It wouldn’t be worth as much for me to just tell you about it and to snap a few foggy cell phone pictures, though, so I brought along Othais of C&Rsenal to help me take high resolution light box photos of these unique and rare firearms.

Today we’ll be looking at H&K’s follow-on design for the SMG I (which didn’t receive that name until today’s weapon was produced, originally it was just the “HK SMG”). If you’re thinking “didn’t we already do this one?”, that’s because the SMG II looks extremely similar to its predecessor. You can compare the two in the image below:

Top: SMG I; bottom: SMG II.

The SMG II is an improved version of the original SMG, with several added features. Instead of using an MP5 magazine, the SMG II uses a new pattern of polymer magazine. The HK21-type sight was replaced with a more classic HK drum sight, and the butt of the stock became a new, smaller sheet metal piece. Perhaps the most significant feature was the pressure selector, located at the front of the magazine. This allowed the SMG II to reliably operate with either high pressure NATO service ammunition or low pressure subsonic ammunition, similar to a regulator setting on a gas operated gun.

If you want to download all of these photos in their full resolution, you can follow this MediaFire link to a zip file containing them.