SIG Sauer developed the SIG-Loc system for the M17 line and later extended it to other models. Rather than a plate stack, the optic sits directly on the slide and is secured by screws from beneath, using five points of contact for a low, solid mount. Because it is SIG-specific, running a non-native optic generally means a SIG-Loc adapter plate.
SIG-Loc (M17 / M18) — SIG’s locking direct-mount optic system
Also called SIG-LocM17 / M18 optic system
The SIG-Loc (M17 / M18) footprint at a glance
- Mounting pattern
- Direct-mount, five points of contact, screws from beneath the slide
- Recoil location
- Five-point direct-mount interface
- Optics on this footprint
- 0 listed below
Cross-compatibility
The SIG-Loc system on the M17/M18 (and related SIG models) lets the optic sit directly on the slide, secured by screws from underneath using five points of contact. It is a SIG-specific interface, so mixing footprints typically means a SIG-Loc adapter plate.
Recommended optics for the SIG-Loc (M17 / M18) footprint
We’re still compiling the optic list for this footprint.