3 Best Red Dot Sights For P320 X5 Legion + Aftermarket Optic Plates

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Referenced Roger Barrera (Get This Gun Here!)

Out of all the pistol sight products we have tested based on their field of view, weight, battery life and money for value. 

Here are the 3 best red dots for P320 X5 pistol that we really like and we will also show you which aftermarket optic plates to get.

Let's check it out...

3 Best Red Dot Optics For P320 X5 Legion


  • Features:2 MOA dot (Red/Green), Motion activated, Fully multi-coated lens, Grade 5 Titanuim housing, CR2032 Battery, 1 MOA/click adjustment
  • Benefits:Fast on target with wide field of view, Solar + battery power providing ~100K hours, Use same mount profile as Trijicon RMR
  • MUST have Mount: Springer Precision RMR Mount

  • Features:2.5 MOA dot, Anti-reflective lens, 1 MOA/click adjustment, Battery saving motion sensor
  • Benefits:Fast TGT acquisition, Perfect for competition, Tool-less top loading battery access, Rugged for home defense
Sig Sauer Romeo3XL 1x35mm Red Dot Sight, 3 MOA Dot Reticle, Aircraft Grade Aluminum, Black, SOR31004
  • Features:1X35mm, 3 MOA dot,  MOTAC, Side loading CR2032 battery tray
  • Benefits:Largest FOV, Fast TGT acquisition for speed and accuracy, Easier battery loading from the side
  • MUST have Mount: Springer Precision ROMEO3 XL Mount

Leupold DeltaPoint Pro - Best Overall

sig p320 x5 with deltapoint pro red dot
Image Referenced ParkerMountainMachine

Since the X-Five Legion slide is already cut for the Leupold DeltaPoint Pro specifically, this optic is the best large window optic for this gun without additional modification.

For the money, this optic lasts way better than Sig Optics and it's a great competition optic.

Besides that... the top-loading battery access makes battery swap easy without sight removal.

Trijicon SRO - Great Optic, But Causes Ejection Issue

Trijicon SRO interferes P320 X5 ejection
Image Referenced forums.brianenos.com

If we had to pick between the DeltaPoint Pro or the Trijicon SRO, we had to go with the DeltaPoint Pro because of the extended length of the SRO body interferes with shell ejection as it sits too close over the ejection port.

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ROMEO3XL 1X35mm - Largest FOV

sig p320 with ROMEO3 XL open reflex sight

If you're a hardcore Sig fan who wants the entire pistol setup top to bottom to be Sig Sauer, then the ROMEO3XL is the optic for you.

What's unique about the ROMEO3XL is its large 1X35mm lens as an open emitter reflex optic, which means the shooter will have an easier time picking up the dot within the window, and also track the dot better.

In general, the ROMEO3XL is stronger and higher quality than the ROMEO1, and you get what you pay, which is a fairly durable optic with all the features like MOTAC, IPX7 waterproof, and others.

What we like most about this optic is its large 1X35mm window and its side battery loading tray for easier battery access without sight removal or anything like that.

Great for setting up a 100% Sig Sauer branded competition gun when shooting the P320 X5 Legion.

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Holosun HS508T - Most Durable

p320 x5 tan with holosun 507c
Image Referenced OuterImpact

Holosun has been the leader in making great optics, very soon it will be added to the list of high-end optics alongside Aimpoint and Trijicon.

For the price, durability, and functionality the overall quality of the HS508T is superior among other non-military contracted optics.

The Holosun HS508T is the upgraded version of the HS507C, and it retains the same features but this time it's built with Grade 5 titanium alloy, which is ~35% stronger than 7075 T6 aluminum without adding extra weight.

What's great for the P320 X Five is its reticle selections, where a new shooter can use the 50 MOA ring as the training wheel reticle for practicing sight acquisition. Once the shooter is comfortable, he/she has the option to switch to the 2 MOA center dot.

When mounting to the P320 X5 Legion, be sure to purchase the aftermarket mounting plates from Springer Precision here.

Common FAQ

Fix Optics Compatibility Issue

What's the problem ? - Sig Sauer ROMEO1 (non-pro) doesn't fit on the new P320 X5 Legion. The X5 Legion slide has a footprint cut to only accommodate the Sig ROMEO 1 Pro and Leupold DeltaPoint Pro.

The P320 X5 Legion slide is made to fit ROMEO1 PRO & Leupold DeltaPoint PRO ONLY, and it doesn't come with additional mounting plates.

The original ROMEO 1 (SOR11000) has a smaller footprint, and the mounting holes are too small for proper mounting using the M4 screws.

Solution? - Buy aftermarket!

Non-Legion P320 X5 Universal Optic Adapter

If you already own the original P320 X5, it's probably a better idea to just get this optic adapter here: Outerimpact P320 X5 Optic Adapter

**DOES NOT FIT X-5 LEGION or X Carry**

But wait... there is more

For X5 Users

For X-Five Legion Users! X-Five Legion users need the M17 optic plates from Outerimpact's website along with some additional screws, and it can accept over 15 popular micro red dot optics.

If you're using any other optics like Holosun, Burris, Trijicon...etc you have to get the adapter plates from either from Outerimpact or SpringerPrecision. (Custom Fitting Maybe Required)

Due to variances in the slide cut and a required tight fit, some minor fitting may be needed to install the mount. 

Wrap Up

For the money, it's almost not worth buying the X5 Legion & a $400 ROMEO1 Pro optic for it. The best optic we really recommend is the Holosun 507C and Leupold DeltaPoint Pro for being way more durable and affordable.

Be sure to check out Outerimpact & Springer Precision for an RMR mount adapter for the Holosun 507C as they share the same mounting dimension.

Hope you find this interesting and helpful, please check out other content on our site.

Ying Xu

US Air Force veteran nuclear weapon officer. Aerospace engineering bachelor's degree from the University of Kansas. Experienced as a certified NRA range safety officer. Working as a search engine expert for BadAssOptic.com