Excerpts:
When Mitch WerBell III began his clandestine weapons business, he set up shop on his property near Powder Springs, Georgia in 1966; in 1967 the company incorporated. Initially, the product line consisted of suppressors for the US M14 and M16 rifles, later adding pistol and submachine gun suppressors. On December 21, 1970, SIONICS officially changed its name to the Military Armament Corporation also known as MAC.
The M10 and M11 suppressors’ rear section had a core that was a simple tube with a series of holes; the area around the core was packed with shoestring eyelets. The front section had a simple baffle followed by two helicals—one right-hand spiral, the other left-hand—designed to slow down the escaping gases. A threaded plate was used to hold the parts and the wipe assembly (consisting of several urethane disks and spacers crimped into a module) in place. A few modern suppressor manufacturers that upgraded the MAC suppressors agree that the original rear section (with the eyelets) is effective.
Why shoelace eyelets? Easily available and they just worked?
The eyelets randomize the motion of the expanding gases which reduces noise. They probably absorb some thermal energy and act a bit like a heatsink.
Wouldn’t they make the gun rattle a lot when walking around, though?
Not enough. They’re packed in tight enough that they don’t rattle around much.
That second pic looks straight from Soldier of Fortune magazine.
