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Does it fit M18 without modifications? — 3 Answers

by Renandave Bisarra, from CA, United States Asked on May 23, 2024

Name Vortex Viper 1x24mm Reflex Red Dot Sight (4.4)
As Low As $123.99 Save Up to 65%
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Answered by Ethan, Gear Expert, from IL, United States, on May 29, 2024

The Vortex Viper 1x24 mm 6 MOA Red Dot Sight is not compatible with the Sig P320 M18. The M18 is optic cut for optics that use the DPP footprint such as the Leupold Deltapoint Pro, Holosun SCS-320, Eotech EFLX, Sig Romeo 1 Pro and more.

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Manufacturer Answer
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Answered by Vortex, Manufacturer from WI, United States, on May 29, 2024

The Defender-ST would be a compatible option with your M18, as the slide is cut to otherwise accept the DeltaPoint Pro footprint, employed by the Defender!

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A
Answered by TroyJ, member, from MN, United States, on May 20, 2025

The Vortex Viper uses the Docter/Noblex red dot sight footprint standard.

You may be able to get a mounting shim/plate for this optic, but that is a question for Sig Sauer.

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