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Nielsen Device: How it Works and Why it's Necessary (Ad-free)
🕑 Added 2025-08-04 12:00:07 +0000 UTCThe Nielsen Device is a type of suppressor mount that allows a suppressor to move forward upon firing and thus allow a recoil-operated firearms to cycle reliably despite the added weight of a suppressor. Popularized by Doug Olsen in the 1980s, they allow pistols to be readily suppressed without needing to tinker with spring strength, slide weight, and suppressor weight. They are not necessary or useful on fixed-barrel pistols, however.
Comments
Shrimpy
Are the holes and cicular radial cut outs etc in the piston necessary for the Nielsen device to work, or are they just there for insuring proper indexing/alignment/venting gas/gas cushioning/etc? Also, I believe there are some (older) suppressors with Nielsen devices that have a racheting system, and the suppressor will incrementally rotate as they fire. Does this serve any function apart from verifying that that Nielsen device is actually working?
Niel Dilworth
From looking at the videos I have a different idea about how the Nielsen Device works; When the pistol is fired the device allows the suppressor to remail at rest instead of being part of the recoiling mass of the pistol and barrel, which allows the slide to function normally. Once the spring in the Nielsen Device is fully compressed the suppressor will be pulled back by the remaining recoil of the barrel. The slide will complete its cycle and the system will ready to fire the next round.
