end wipe, plus the end caps. Sionac also offers a suppressor parts pack for the .45, 9mm and .380, obviously designed for the Ingram weapons. In 1982 they added a threaded, long barrel for the M1911A1 so it could be used with an Ingram style suppressor.
In terms of testing, the Sionac .22 caliber suppressor indicated a dB level of 70, while their larger .380 and .45 units came in at 75 dB. which is about the level of electric typewriter noise. For comparison purposes, Sionac's booklet describes as "painful" the 130 dB of a pneumatic hammer, while the threshold of human hearing is 5 dB. Of the kit suppressors 1 have seen, the Sionac models are among the best, the rival of commercial designs.
The Special Missions Group, Ltd. first appeared in print in January of 1981 with a Shotgun News ad selling suppressor kits for the Ruger RST and the High Standard pistol for SI25, plus the AR7 and a universal .22 rifle model for $150. All parts were 4130 ordnance steel or T-6 aircraft quality aluminum. Listed as a post office box in Soda Springs, California, the Special Missions Group offered full instructions, including those for legal activation. An inquiry to the company brought a cryptic response initialed "P. D. S." from one who called himself general manager. "Company policy is not to release personal information or particulars about the company to journalists or members of the press," he wrote.
Later, however, D. W. Lambert, Special Mission Group product design director, did note that the company had a prototype suppressor for the AR15/M16 and the AR180, claiming sound reduction to that of a .22 rimfire. P. D. S. noted that their Ingram suppressor was "very slightly more effective than the factory unit." They were also
Was this article helpful?