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Holosun
Overview
The Holosun 403B Micro Red Dot Sight features a 2 MOA dot that provides precise aiming capabilities for various shooting applications. Designed as a red dot optic, it allows for rapid target acquisition and excellent visibility in a variety of lighting conditions. This sight is frequently found on builds featuring a pistol gas system, particularly in 5.56 NATO caliber configurations.
Specifications
Available Merchants(5)
Prices checked
Stock Alert
Build history on GunPartPicker
Builders have added the Holosun 403B Micro Red Dot Sight 2 MOA - HS403B to their builds on GunPartPicker. Since April 2026, it ranks #234 of the 584 optics builders have added. Builds with this optic are mostly chambered in 5.56 NATO (64%, then 300 Blackout 21%), split between pistol-length (50%) and carbine-length (33%) gas systems, and mostly AR-15 (90%, then AR-9 11%).
It was out of stock everywhere we track every time we checked in October 2026, and today none of the 5 retailers we track has it in stock right now. Listed prices start at $112.49 at Brownells for when it comes back.
Updated · from real builds on GunPartPicker · Prices checked · refreshed daily across 37 retailers
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Read the guide: AR-15 Red Dot & Optic Guide →Check it against the live catalog:
Frequently Built With
The part most often added in each category by the builds that include this one
BLEM PSA AR15 Complete Classic Stealth Lower, Black
Aero Precision AR-15 Stripped Upper Receiver, No Forward Assist Black
Streamlight ProTac Rail Mount HL-X 1000 Lumen Weapon Light with Tapeswitch
Magpul RVG Rail Vertical Grip - Black
Breek Arms AR-15 Warhammer MOD2 Ambidextrous Charging Handle Black
Daniel Defense Collapsible Mil-Spec Buttstock, Brown - 21-091-04179-011
Build Configuration Breakdown
Aggregated and anonymized data showing how builders use this product
PlatformBased on real build data showing which platform (AR-15, AR-10, AR-9) builders pair with this product.
CaliberBased on real build data showing which calibers builders choose alongside this product.
Gas SystemBased on real build data showing which gas system lengths builders use with this product.
Builds Featuring This Part
See all builds →Builds in the community that include the Holosun 403B Micro Red Dot Sight 2 MOA - HS403B
| Build | Parts | Total |
|---|---|---|
 | 31 | $2962.06 |
 | 20 | $1019.47 |
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