Old School MAC Cans

By Frank Iannamico

During the 1960s–1970s there were very few companies manufacturing suppressors, AKA silencers, in the US. Few/none were making them for the civilian market, which was virtually non-existent at that time. One of the few companies of that era was SIONICS which stood for “Studies in Operational Negation of Insurgency and Counter Subversion.” SIONICS’s business was mainly directed at governments—US and foreign.

SIONICS Incorporated

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.

SIONICS Sound Suppressors

Most of the suppressors that SIONICS/MAC designed and sold, used rubber discs called wipes to help suppress the muzzle report. The life expectancy was 200 rounds before the unit’s efficiency deteriorated and the wipes required replacement. A wipe replacement module was available as a separate item. Mitchell WerBell III’s achievements in suppressor design were often regarded as the most significant advancements since Hiram Maxim’s silencers were patented in 1909. Some of WerBell’s best-known suppressors were those made for the MAC submachine guns.

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. The front section with the helicals was the area in need of improvement. In 1972, the factory price for a MAC suppressor was $57.00. From 1971 to 1973 the Military Armament Corporation produced 1,138...

This article first appeared in Small Arms Review V22N8 (October 2018)
and was posted online on August 24, 2018


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