What red dots fit FNX 45 tactical?

Here are 7 best FNX 45 tactical red dot sight. We have tested a handful of sights based on their durability, compatibility, reticle, battery life and cost.

The large MOA dot sight works exceptionally well for users with astigmatism, helping them acquire the dot faster based on my thorough experimentation and hands-on experience.

Let's check them out:

Best Red Dot For FNX 45 Tactical

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Top 3 Options

Best Overall

Holosun 507C

best red dot for fnx 45 tactical
  • Multi reticles
  • Duty Grade
  • 50K hr battery + solar

Largest FOV

Trijicon SRO

fnx 45 tactical red dot
  • 5 MOA dot
  • Large window
  • Top battery loading

Best Durability


fnx 45 red dot
  • 6.5 MOA dot
  • Duty Grade
  • 50K hr battery life

Holosun HE507C X2 - Best Overall

fnx 45 tactical red dot
The Holosun HE507C X2 serves as a top-notch alternative to the Trijicon RMR for the FNX 45 Tactical. It offers the same durability, RMR mounting compatibility, and comes at a more affordable price.

Bigger Buttons - Enlarged adjustment buttons for better reach Upgraded from the previous model. 

Very Long Battery life - The Shake Awake technology and solar panel significantly extend the battery life to over 50,000 hours. A motion sensor turns the reticle on and off to save battery power, and the Solar fail-safe power activates instantly when the battery runs out, ensuring that the optic stays on at all times.

No Hassle Battery Swap - You can access the CR1632 battery from the side tray, eliminating the need to remove the sight for a battery swap and re-zeroing. In my honest opinion, this design is much better than the Trijicon RMR.

At this price point, users can save a ton of money while getting a duty grade red dot sight for your FNX 45 Tactical.

Read HS507C X2 Review


  • Much more affordable than Trijicon RMR
  • Uses RMR footprint
  • Long battery life + motion sensor aviation + solar power
  • No sight removal required for battery swap
  • Cons

    • Open emitter design attracts dirt
    • Solar power doesn't work indoor if ambient light is too weak
    • No FDE model for the FDE FNX 45, but it's not a big deal
    best red dot for fnx 45 tactical

    The Trijicon RMR red dot sight sets the gold standard for micro pistol reflex sights and is the top choice for handguns, rifles, and shotguns. When it comes to the FNX 45 Tactical, the RMR RM07 with the 6.5 MOA is the best RMR sight available.

    Improved Accuracy - Super clean and fine 6.5 MOA red dot works for shooters with astigmatism with super clear dot clarity (Or try larger sizes)

    Multi Color Options - Color matching your FNX 45 Tactical RMR with either Black or FDE color.

    Built For Handgun Slide Cycling - The RMR Type 2 is specifically built to withstand handgun slide G force. The new battery compartment design grips the battery tighter to prevent loose electrical contact

    Slide Racking Assist - Racking the slide one handed effortlessly by pressing the optic window frame against hard surfaces when necessary. This gives the shooter large surface area to charge the slide 


    • Gold standard micro red dot
    • Duty grade quality
    • Long battery life
    • Multiple dot sizes to choose from


    • Bottom access battery compartment

    Trijicon SRO (5 MOA) - Largest FOV

    fnx 45 red dot

    Use FN RMR plate or CHPWS for direct mount

    Why we picked the Trijicon SRO - The Trijicon SRO shares the RMR mounting footprint and enables quick target acquisition, making it easy to place the red dot in the center of the lens. I find this feature extremely helpful, especially when my eyes are slightly off-center from the optic. The window is just big enough for me to quickly reacquire the dot without any trouble.

    In addition, the FNX 45 Tactical 's 1911 style grip angle enables the shooter to acquire the Trijicon SRO sight picture right away without being too low or too high. You can also experiment with different size grip backstraps to slightly change the grip angle that's best for you.

    Easier Battery Access - Load/Replace battery right from the top! No sight removal or re-zero required

    Field Durable - The 7075 T6 forged aluminum housing makes the sight super rugged construction to survive drop, however, not near the lens like the RMR

    Ambient Light Brightness - The user can use the auto brightness mode on a sunny day or lock the brightness settings

    Better Follow Up Dot Acquisition - Increased sight acquisition speed including consistent fast follow-up shots without losing the dot inside the window.

    See Trijicon SRO review


    • Very large FOV for dot tracking
    • No zeroing or sight removal required for battery swap
    • Same RMR footprint
    • 1 MOA, 2.5 MOA and 5 MOA
    • Lockout mode


    • A bit pricey
    • Not duty grade lens construction like the RMR

    Trijicon RMR HD - New 3rd Gen RMR

    rmr hd

    The brand new 2023 Trijicon RMR HD offers a larger window close to the Trijicon SRO, the mounting footprint is still the same as RMR, and the optic features a forward light sensor that automatically adjust the reticle brightness based on the target's lighting information.

    Under significant light condition change either with pistol light use or bright sunlight, the reticle will be at the perfect dot brightness for target shooting and real world duty use.


    • Larger FOV than RMR
    • Top loading battery
    • Same RMR footprint
    • Real time brightness control based on target brightness


    • A bit pricey
    • May interfere with ejection port

    Holosun 509T - Best Weatherproof

    fnx 45 tactical accessories

    The Holosun 509T X2 red dot sight features a fully enclosed body design to keep debris from entering the optic. This is a fully weatherproof optic for the FNX 45 Tactical in any weather conditions. The fully multi coated lens is nice, but there is slight window edge distortion.

    Titanium Durability – The optic can handle heavy recoil impulses and slide racking against hard surfaces. 

    32 MOA Reticle + 2 MOA red dot - Same reticle system as HS507C, But without the 32 MOA Only mode

    Battery Lasts A Long Time – 4+ years of long battery life + Solar Failsafe to keep the sighting system operational

    Clamp Mount - Tighter and much more secure mount (CHPWS adapter plate)

    Motion Activated Reticle –  Shake Awake technology just like Holosun 507C

    Leupold DeltaPoint Pro - Additional Lens Durability

    fn fnx 45 tactical red dot

    Use a spare M&P Core DPP mount plate)

    fnx 45 optic footprint

    See torque specs and how to install it here

    The DeltaPoint Pro offers a field of view size similar to the Trijicon SRO and is considerably more budget-friendly. However, it's ranked lower because it necessitates proper fitting or the use of an aftermarket optic to function effectively.

    Extra Housing Protection - The added lens hood protects the optic from receiving direct impact which increases durability and makes it fail-proof.  

    Easier Battery Access - Load/Replace battery right from the top. No sight removal or re-zero required. 

    Read DeltaPoint Pro Review here


    • As large as Trijicon SRO window
    • Additional lens hood protection
    • No sight removal required for battery swap


    • Single button to cycle through brightness adjustment
    • Requires mods or additional plates to install

    Swampfox Justice - Tapered Field of View


    It's worth noting the Swampfox Justice red dot sight due to its tapered field of view that slightly enlarges the window size, along with its compatibility with the Trijicon RMR footprint.

    The optic's body is constructed from 7075 T6 aluminum housing and offers a top load battery access, similar to the Trijicon SRO.

    Overall, this optic provides an affordable option to start with for your FNX 45 Tactical.


    • Enlarged window design
    • Top loading battery compartment
    • Lightweight


    • Tapered FOV isn't as big as advertised


    FNX 45 Tactical Red Dot Compatibility

    The FNX 45 Tactical comes with sight mounting kit with plates and screws for the following sights:

    Any RMR footprint sights and Docter Sight.

    Which Optic Plate Fits The Leupold DeltaPoint Pro? 

    The Leupold DeltaPoint Pro can be mounted with Leupold Part #171203

    The optic can be mounted directly to the slide without a plate, but requires some material trimming to fit the optic (NOT recommended)

    Pick Optic Color: FDE or Black?

    For aesthetic, it's all based on your preference.