Forget Threading: The 1960s Tech That Screws Today’s Better SMG and PCC Suppressor Mounts

Fact: Tri-Lug Barrels are the oldest, easiest, and one of the best ways to quickly mount a suppressor. However, the attachment style is also limited in what it can do and, sadly, is overlooked. Where did Tri-Lug or 3-Lug come from? In Oberndorf, Germany, in the early 1960s, Helmut Baureuter, Manfred Guhring, Tilo Moller, and Georg Seidl cooked up probably the most mature sub gun of the 20th Century– the Heckler & Koch MP5. Recycling a roller-locked action first used on legendary machine guns in WWII and carried over to the G3 7.62 NATO battle rifle, it proved durable enough to become legendary. It also had a funky, albeit innovative, barrel accessory mounting system on the muzzle: three equal-sized (roughly 0.310-inch) raised external lugs, spaced equally about 120 degrees apart center-to-center around the outside of the barrel, and ramped towards the muzzle. These lugs were not an afterthought, welded, screwed, or pinned in, but something machined directly from, or forged with, the…