The Holosun HS403 is a series of compact DSLR-style red dot sights, manufactured by Holosun Technologies, designed to equip civilian AR-15, AK and M4 semi-automatic rifles and rifles. This family of sights is distinguished by a 2 MOA red dot reticle, IP67 waterproofing, an exceptional battery life of 50,000 hours and a lightweight aluminum body of about 100 grams, all at a price significantly lower than the premium references on the market.
History and Development of the Holosun HS403 Series
Holosun Technologies is an American-Chinese company founded in 2013, with its US headquarters in City of Industry, California. The brand has quickly established itself in the global tactical optics market by offering sights that combine reliability, lightness and competitive prices compared to established references such as Aimpoint and EOTech. Holosun’s technological know-how is based on experience in precision optics, initially developed for industrial applications, before being adapted to weapons equipment.
The HS403 series was launched as an entry-level line aimed at the civilian sports market, in response to the growing demand for affordable yet reliable red dot sights. It takes the design principles of the Aimpoint Micro-type systems — open sight, 2 MOA reticle, Picatinny mount included — and offers them at a fraction of the price. The series was an immediate commercial success in North America, Europe and Asia, where it has established itself as the go-to choice for shooters looking to equip a training or recreational rifle without investing in high-end military equipment.
The range has gradually been expanded to meet different user profiles. Each version retains the same basic optical platform, while varying the control system and power supply. The price positioning of the series (70–150 CHF depending on the model) makes it a rational choice for a first red dot sight or an economical replacement viewfinder.
Technical Specifications
| Feature | Specification |
|---|---|
| Designation | Holosun HS403 (Series) |
| Manufacturer | Holosun Technologies (China/USA) |
| Type | Micro reflex viewfinder (red dot) |
| 1x magnification | (non-magnifying) |
| Objective Lens Diameter | 20 mm |
| Red Dot Reticle | 2 MOA |
| Reticle color | Red (standard) / Green (GR variants) |
| Impact adjustment | 1 MOA per click |
| Brightness settings | 12 levels (10 day + 2 night vision compatible) |
| CR2032 | Battery |
| Battery life | 50,000 h (medium level) |
| Multi-layer anti-reflective | optical coating |
| Cast aluminum housing | , black anodized finish |
| Dimensions | 69.9 × 36.3 × 41.1 mm (L × W × H) |
| Weight | ~100 g (without mounting) |
| IP67 waterproof | (submersible up to 1 m) |
| Mounting Included | Lower 1/3 Co-witness (41.4 mm) + Low Mount (19.1 mm) |
Operation and Technical Particularities
The HS403 series uses open-reflex sight technology: the bright reticle is projected onto an angled partially reflective lens, allowing both eyes to be aimed without reducing the field of view or tunneling. At 1x magnification, the sight does not change the perception of the target, which is ideal for fast engagements at close to medium range. The point of 2 MOA (Minutes of Angle) corresponds to approximately 5.8 cm at 100 meters, providing sufficient accuracy for sport shooting and training.
All models in the series share the same black anodized cast aluminum housing, the same lenses with multi-layer anti-reflective coating, and the same IP67 resistance (dustproof and submersible up to 1 meter deep). The 12 brightness levels, 2 of which are compatible with light-intensifying night vision goggles, allow for use in all lighting conditions, from full tropical sun to total darkness. The sight comes with two Picatinny mounting heights — Lower 1/3 Co-witness at 41.4mm and Low Mount at 19.1mm — to accommodate different rifle configurations.
Variants and Versions
The HS403 series comes in three main variants that share the same optics but differ in their control and power system. The HS403B is the simplest entry-level version: CR2032 battery in the rear position accessible by screw door, two side push buttons (+ and –) to navigate between the 12 brightness levels. Its sleek design makes it particularly familiar to Aimpoint users. The HS403C adds a Solar Failsafe solar panel on the front: outdoors, the viewfinder runs on solar energy and only uses the CR2032 indoors or at night, significantly extending the effective battery life. The HS403R replaces the push buttons with a side-mounted rotary switch that integrates the battery compartment directly into the dial — an ergonomic solution that allows the battery to be changed without tools and without removing the viewfinder. The HE403 series offers “Elite” versions with a more robust alloy housing. The GD (Gold Dot) and GR (Green ) suffixes indicate a gold or green reticle respectively for better visibility depending on the environment.
Users and Marketplace
The HS403 series is primarily intended for the civilian sports market. Shooters practicing dynamic shooting (IPSC, 3-Gun), target shooting or simple plinker training are the core target. The universal lightness of the range (~100 g) makes it attractive for configurations seeking to minimize weight, especially on civilian AR-15, AK-pattern and M4 rifles. On the European market, the HS403 series is distributed by many specialized dealers in Switzerland, France, Germany, Austria and Belgium. Some private security units in countries with limited budgets have also adopted these sights as a service optics, due to their excellent price-performance ratio.
Compared to its direct competitors, the HS403 series is clearly positioned: it offers superior optical performance and reliability to generic low-cost sights (Bushnell TRS-25, UTG, etc.) while costing five to ten times less than an Aimpoint Micro T-2 (~1,000 CHF) or an EOTech (~600 CHF). It is a credible alternative for the civilian shooter who does not need the mil-spec-certified robustness of premium military optics.
Civil Possession in Switzerland
In Switzerland, the Holosun HS403 series consists of optical accessories that are not subject to any specific regulations. The purchase is free for any adult, without a license required for the accessory itself. The use is conditional on the legal possession of the weapon on which the sight is mounted. For a semi-automatic rifle (AR-15, SIG 550 civil, AK civilian, etc.), the acquisition requires a weapons acquisition permit issued by the competent cantonal authority, in accordance with the Federal Weapons Act (Firearms Act). The applicable conditions include: being at least 18 years old, not being under guardianship of general application, and not presenting a reason for refusal within the meaning of Art. 8 para. 2 Firearms Regulation. The models of the HS403 series are available from many Swiss gunsmiths and online shops specializing in firearms accessories.
Conclusion
The Holosun HS403 series represents one of the most consistent offerings on the market for the civilian shooter looking for a reliable and cost-effective red dot sight. With 50,000 hours of battery life on the CR2032, IP67 waterproofing, a rugged aluminum casing and three variations covering all usage profiles — HS403B for simplicity, HS403C for maximum autonomy, HS403R for ergonomics — the range offers a complete solution at an affordable price. It perfectly embodies Holosun’s philosophy: serious performance at a democratic price.
