I'm thinking this looks like a Scionics equipped M40. I've not seen this photo before. That must be Werbell in the background pointing?
Historical Firearms - SIONICS Incorporated & The MAC-10 In the early...
SIONICS Incorporated & The MAC-10 In the early 1960s a former OSS operative and mercenary Mitchell WerBell III set up a company dedicated to the development of cheap and efficient sound suppressors for automatic weapons. Following the Japanese attack on Pearl Harbour WerBell had joined the US...
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