Comparison

    Holosun LS321G vs Holosun IRIS-GR3: Side-by-Side Comparison (Specs, Handling, Real Use)

    Key Differences at a Glance

    • Form factor & weight: Holosun IRIS-GR3 is notably more compact and lighter (6.4 oz) than Holosun LS321G (8.64 oz). (holosun.com)
    • IR illuminator technology & output: Holosun IRIS-GR3 uses a VCSEL IR illuminator rated at 60 mW; Holosun LS321G is an older-generation design and Holosun’s current product page does not publish an illuminator mW figure. (holosun.com)
    • Waterproof rating: Holosun IRIS-GR3 is listed as IPX8; Holosun LS321G is listed as IP67. (holosun.com)
    • Controls & switching: Holosun IRIS-GR3 is built around newer ergonomics (central fire button, rear selectors, low-profile two-button Crane-plug remote with VIS override per Holosun). Holosun LS321G uses a more traditional rear selector plus top activation and a included remote cable switch. (holosun.com)
    • Lifecycle/status: Holosun LS321G appears under Holosun’s “discontinued model” category; Holosun IRIS-GR3 is a current production model in the IRIS series. (holosun.com)

    Current Market Position & Pricing

    • Manufacturer MSRP (useful as an anchor):
    • Availability reality (U.S. market):
      • Holosun LS321G being categorized as discontinued by Holosun generally correlates with a market that’s primarily dealer old-stock and secondary-market. That typically means wider price dispersion and less predictable warranty/support experience depending on provenance.
      • Holosun IRIS-GR3 is actively marketed by Holosun and positioned as the newer compact “integrated rifle IR system,” so availability tends to follow current distributor allocations.

    Pricing note (important): You asked for “current retail pricing across multiple retailers” and “stock levels.” I can verify MSRP and official specs from Holosun, but retailer pricing/stock data would require citing retailer pages or shopping/marketplace sources—which your citation rules prohibit. If you want, I can still summarize pricing trends without citing retailer pages (as non-cited observational commentary), but that would not meet your “source citation” standard.

    Specifications Comparison

    SpecHolosun LS321GHolosun IRIS-GR3
    Device typeCoaxial visible green + IR pointer + IR illuminatorDual laser + IR illuminator (co-aligned)
    Visible laserGreen, Class IIIa; listed output < 5 mWGreen (or red variant family); visible output < 5 mW, Class 3R
    IR laser (pointer)IR laser present; Class 2 (per Holosun description)IR pointer output < 0.7 mW, Class 1
    IR illuminatorIncluded (Holosun lists “IR illuminator,” no mW on product page)VCSEL 60 mW IR illuminator; beam 15–150 mrad
    Adjustment0.5 MOA per click; ±50 MOA0.5 MOA per click; ±50 MOA
    Dimensions (in)3.6 × 2.2 × 1.63.2 × 1.97 × 1.34
    Weight8.64 oz6.4 oz
    BatteryCR123ACR123A
    WaterproofIP67IPX8
    Housing7075-T6 aluminum; MAO finish7075-T6 aluminum; hard anodize
    Vibration rating1000G1000G
    What’s in the box (manufacturer list)QD mount, remote cable switch, T10 L key, manual, CR123AHolosun page indicates a two-button remote switch w/ Crane plug + VIS override; manual link present (box contents not fully enumerated on the page excerpt)

    Source basis: LS321G specs from Holosun product page; IRIS-GR3 specs from Holosun product page and IRIS manual (for wavelengths/modes). (holosun.com)

    Performance and Accuracy

    • Zeroing/precision potential: Both list 0.5 MOA per click adjustments and ±50 MOA travel, which is consistent with being able to zero at typical carbine zero distances (e.g., 50/200) assuming proper mounting and rail alignment. (holosun.com)
    • IR illuminator performance (practical implication):
      • Holosun IRIS-GR3 explicitly specifies a 60 mW VCSEL IR illuminator and an adjustable beam pattern (15–150 mrad). In practice, that combination tends to matter most for helmet-mounted NODs + carbine use where you want both flood and a tighter spot option without changing gear. (holosun.com)
      • Holosun LS321G provides an IR illuminator and IR pointer, but Holosun’s page does not publish illuminator power/beam metrics. That makes objective “reach” comparisons difficult on paper without independent photometric testing.
    • Reliability/durability signals from published specs: Both are 7075-T6 housings with a stated 1000G vibration rating. Holosun IRIS-GR3 is listed IPX8 vs LS321G’s IP67, suggesting a higher water-ingress rating on paper. (holosun.com)

    Ergonomics and Handling

    • Profile on the rail: Holosun IRIS-GR3 is smaller in every listed dimension and about 2.2 oz lighter, which reduces rail bulk and can improve balance on shorter handguards or when you’re already stacking a white light, switch, and sling hardware. (holosun.com)
    • Controls philosophy:
      • Holosun IRIS-GR3 is designed around ambidextrous activation (central fire button) and rear selectors, plus a Crane-plug remote with a VIS override (per Holosun’s overview and IRIS manual). (holosun.com)
      • Holosun LS321G uses a rear-facing selector that cycles visible/IR/illuminator combinations, plus a top button and included pressure switch; it’s straightforward but typically occupies more rail “real estate” and has a taller silhouette than the IRIS family. (holosun.com)

    Features and Accessories

    • Remote switching:
      • Holosun LS321G: includes a remote cable switch in the box per Holosun. (holosun.com)
      • Holosun IRIS-GR3: designed around a two-button remote with Crane plug and a VIS override (per Holosun overview; IRIS manual also mentions a waterproof remote cable switch w/ VIS override). (holosun.com)
    • Illuminator focusing: Holosun IRIS-GR3 has a beam adjustment slider for fast focus changes. This is a meaningful feature difference if you actually use the illuminator as your primary IR “light” under NODs. (holosun.com)
    • Mounting: Both are Picatinny-mounted units; Holosun lists a QD mount in the LS321G box contents. (holosun.com)

    Real-World Applications

    • Night-vision carbine use (training, LE-style workups, hog/predator under NODs where legal):
      • Holosun IRIS-GR3 is the clearer fit when you value compactness + VCSEL illuminator output + variable beam in one unit.
      • Holosun LS321G can still fill the same role, but it’s bulkier and (based strictly on published Holosun specs) less transparent on illuminator performance.
    • General-purpose “laser for occasional NV crossover”:
      • Holosun LS321G being discontinued can make it attractive when found at a favorable price, but your decision should account for supportability and parts/switch ecosystem over time.
    • Daylight use: Both provide a visible green aiming laser and high/low settings (IRIS manual explicitly calls out high/low). Remember that visible lasers are not a replacement for a properly zeroed day optic; they’re a supplemental aiming reference with tradeoffs in signature and precision at distance. (holosun.com)

    Expert and User Reviews Analysis

    • What I can substantiate with your source restrictions:

      • Holosun positions Holosun IRIS-GR3 as a redesigned, lower-profile, lighter system relative to the LS321 series, and publishes concrete IR illuminator output and beam pattern specs. (holosun.com)
      • Holosun categorizes Holosun LS321G under “discontinued model,” which matters when weighing long-term support and consistent availability. (holosun.com)

    • What I cannot do under the current citation rules:

      • Cite major retailer review sections, forum threads, or third-party reviewers unless they’re manufacturer/official sources. (You asked for “recent reviews and user feedback,” but most of that lives on forums, YouTube, and retailer pages.)

    If you approve citing a limited set of non-retail industry sources (e.g., reputable training outlets, established review publications, or relevant standards bodies), I can add a properly sourced “reviews synthesis” section.

    Final Verdict

    • Choose Holosun IRIS-GR3 if you want the newer compact architecture with clearly published IR-illuminator performance (VCSEL 60 mW) and a variable beam system in a smaller/lighter package. (holosun.com)
    • Choose Holosun LS321G if your priority is finding a unit at a lower street price (common for discontinued models) and you’re comfortable accepting the tradeoffs that come with an older, larger housing and a less-defined published illuminator spec set from the manufacturer. (holosun.com)

    Sources

    Holosun. "LS321G." HOLOSUN. n.d. https://www.holosun.com/index.php/products/laser-weaponlights/321/ls321g.html Holosun. "IRIS-GR3." HOLOSUN. n.d. https://www.holosun.com/products/laser-weaponlights/iris-laser-series/iris-gr3.html Holosun. "321 (Discontinued Model category page)." HOLOSUN. n.d. https://holosun.com/products/discontinued-model/laser-weaponlights/321.html AAWEE (PDF host). "IRIS-GR3 / IRIS-RD3 Konsumentlaserenhet – Bruksanvisning (SWE)." aawee.fi. (PDF date not shown). https://www.aawee.fi/storage/product_files/3/IRIS-GR3-HOLOSUNIRISKonsumentlaserenhetbruksanvisningSWE_7a0cc62fb37e83dc30bd7a370b224371.pdf AAWEE (PDF host). "IRIS-GR3 / IRIS-RD3 Kuluttajalaserlaite – Käyttöohje (FIN)." aawee.fi. (PDF date not shown). https://www.aawee.fi/storage/product_files/3/IRIS-GR3-HOLOSUNIRISkuluttajalaserlaitekayttoohjeFIN_34173f4ab132474faf7ab2a96eb9ea15.pdf