So you bought yourself a Sig P320 – good choice – and now you want to optimize your optics (we don’t blame you). Well, you’re in the right place because we’re going to show you how to choose the best red dot for a Sig P320. Naturally, Sig wants you to keep it in the Sig family by using one of its red dots, but that doesn’t mean you can’t think outside the box. In reality, Sig does make a good red dot, just not the best for a P320 – shh, don’t tell them that.
Plus, everyone has his own preferences. While you might prefer what Sig has to offer, there’s a strong likelihood that you prefer another company’s reflex sight. The good news is that since the P320 is one of the most popular firearms, optics companies are aware of this and have adapted. In this guide, we chose red dots that offer special adapter plates to fit your 320.
Also, there’s always the option to have your P320 slide milled to accept just about any red dot. And while that may sound intimidating, there are professionals who can machine it for a relatively low price. So, there’s really no limit to what you can do with your P320’s optics.
How to Choose a Red Dot for a SIG P320
When choosing a red dot for any firearm, there are certain factors to consider. Below is a list of factors we considered when creating this guide:
- Compatibility – If you want to skip milling, machining, or modifying your P320, you have two primary options in this guide. Beyond that, there’s the option to choose a sight with an adapter plate or to mill the slide.
- Size & Weight – We prefer reflex sights for a P320 to keep added weight to a minimum. Plus, reflex sights are incredibly light. Top brands offer some top-notch red dots, including Sig.
- Battery Life – Our favorite red dots have the longest battery life because we don’t like swapping out batteries too often. Surely, you feel the same, and depending on how often you carry your Sig, you’ll appreciate a longer battery life.
Beyond those three general considerations, you’ll find other key points baked into the reviews below. Now, let’s see what’s available to you.
Reviews: Best SIG P320 Red Dot
Under each review, we share tips, key features, and the pros & cons of owning each sight. By the end, you’ll know without a doubt which red dot is best for your Sig.
#1) Leupold DeltaPoint Pro
Depending on which model P320 you own, Leupold’s DeltaPoint Pro is the best red dot for a Sig P320 with no mods required. Currently, the M17, M18, XFIVE Legion are compatible, however, it’s always wise to consult Sig to check for compatibility issues with your exact model. Also, there’s the chance of losing the factory rear sight when mounting the DPP. At any rate, the DPP is still our favorite red dot for the P320.
First, the DPP sight is crystal-clear and bright in low-light and bright light. If you ever had to deal with glare, you can forget that problem with this sight. Second, it’s built like a tank with aluminum shrouded in spring steel, yet it weighs just 2 oz. Third, it’s an excellent choice for people with poor eyesight or aging eyes because of the stellar image quality and wide FOV.
One unique feature you’ll like is the battery-conserving motion detection that automatically turns off the reticle after 5 minutes of inactivity. Then, once the sight detects motion, it automatically reactivates. As a result, this feature and the overall efficiency of the sight offer up to 300 hours of battery life on high (up to 1,600 on low). All things considered, if you want crystal-clear premium optics on your Sig, Leopold’s DPP is a red dot that’s worthy of your attention first.
- Crystal-clear, bright glass
- Wide FOV with the ability to acquire your target with both eyes open
- 2.5 MOA and 6 MOA available
- Motion detection technology to extend battery life
- Waterproof to 66 ft
- Excellent performance in bright and low light
- No mods required for most P320 models
- Lifetime Guarantee
- Compatibility issues are possible (be sure to check if you need to do mods or buy additional parts)
- Battery life isn’t on par with our next pick
- Pricier than other options
#2) Trijicon SRO Red Dot Sight
Most optics buffs agree that Trijicon manufactures the best red dots on the market. So, it’s only natural that a Trijicon sight would land on our list of best red dots for a Sig P320. Unlike our top pick, the SRO won’t fit your P320 right of the box. The solution is to use the RMR/SRO Adapter Plate for Sig Sauer P320 models, including the X-Carry. The good news is that the plate is fairly easy to find. The bad news is it’s not cheap.
Though, when you consider what Trijicon brings to the table, the price might take a backseat. Firstly, the SRO features the crispest red dot on any sight we’ve ever used. Secondly, the 8 brightness settings with 2 night vision modes make the SRO a 24/7 performer no matter the time or weather. Third, the 7075-T6 aircraft-grade aluminum construction makes for an incredibly lightweight and durable red dot.
With a weight of just 1.6 oz, you won’t even know it’s there. Lastly, where the Trijicon shines above its competitors is battery life. On a single battery, the SRO offers over 3 years of continuous use at setting 4 of 8. Then, once it does finally come time to replace the battery, the top-loading design makes the process painless.
- Longest battery life
- 8 brightness settings with 2 night vision modes
- Waterproof down to 10 ft
- High-quality aluminum construction
- 1, 2.5, and 5 MOA available
- Reliably parallax-free
- Easy windage and elevation adjustments
- 5-year warranty
- Requires an adapter plate
- Highest cost
- You might like the RMR better
#3) Sig Sauer Romeo1Pro
Now, if you want to stick with Sig, the Romeo1Pro is the current winner for your Sig P320. Presently, the Romeo1Pro is compatible with the M17, XFive Legion, XCompact, XFull, and Pro Series 320 models. With no chance of compatibility issues and no need to buy an expensive adapter plate, you’ll save some bucks right off the bat. Next. the Romero1Pro sports some worthy upgrades including aircraft-grade aluminum and better brightness.
The key upgrade for better brightness is the new point-source emitter. With this new component, the dot is crisper and clearer in all environmental & light conditions. Additionally, with 12 brightness settings, it’s almost impossible not to match the brightness to all day and night conditions.
As for the glass, Sig is known for featuring competitively clear glass amongst the top brands. The Romero1Pro features Sig’s SpectraCoat for enhanced light transmittance and edge-to-edge clarity. For reference, this is the same coating Sig features on its popular rangefinders. Finally, the ruggedized protective shroud only boosts the durability of the already-durable aluminum.
- No compatibility issues or additional purchases required
- Extreme durability
- Premium lens coating for bright, clear performance
- 12 brightness settings
- 3 and 6 MOA available
- 20,000+ hours of runtime
- 5-year warranty
- Does not fit the Romeo1 slide cut-out
- Installation instructions could be better
#4) Vortex Optics Viper
Coming in at number four on our list is our top bang-for-your-buck red dot for a Sig P320. So, if the Trijicon SRO was too rich for your blood or outside of your budget, then the Viper is a top alternative. First, it’s important to note that this red dot is not compatible with the P320 without milling or a special optics cut. Despite the added cost, the Viper is still more affordable than our top three picks.
If you’re unfamiliar with Vortex, the company has made a name for itself over the past decade, rising to become one of the most popular and well-known optics brands. A couple of advantages of choosing Vortex are its top-notch glass for affordable prices and its ironclad lifetime warranty. In fact, a lot of hunters choose Vortex because they know how great the warranty service is – a truly hassle-free experience.
Now, regarding the Viper, this red dot is super low-profile and lightweight at just 1.03 oz. Additionally, it features Vortex’s Fully Multi-Coated Lens system for bright, crisp performance in all light conditions. Plus, expect parallax-free performance and an extremely durable sight with Vortex’s scratch-resistant ArmorTek coating.
- A good affordable alternative to our top three picks
- Waterproof construction
- Low-profile, lightweight design
- Premium lens coatings for brighter glass
- Vortex VIP lifetime warranty
- Rugged construction
- Requires milling or special adapter
- Must be removed to change batteries
- Windage and elevation adjustments are not the easiest
#5) Aimpoint Acro P-1 Red Dot Reflex Sight
Well, we chose to end our guide with a bang because Aimpoint makes some of the finest red dots in the world. Compared to our first four picks, the Acro P-1 takes a different approach with its fully enclosed housing and enclosed optical channel. The advantage here is that nothing can obscure the dot, including snow, dirt, and other debris. Hence, there’s never a need to worry about that dot failing you during a critical moment.
Next, Aimpoint doesn’t skimp on its glass. Expect clear glass on par with Trijicon that some say is even clearer than Trijicon. Make no mistake, this is one of the nicest red dots on the market for pistols. After that, the next advantage is that Aimpoint manufactures an Acro adapter plate for Sig P320 handguns (item# 200525 in its catalog).
Several final highlights are the durable construction that’s waterproof to 80 feet, optimal 3.5 MOA, 1.5-year battery life at setting 6, and top-notch performance in bright light with no glare. All in all, the enclosed design and overall quality of the Acro P-1 landed it on this list of best red dots for a Sig P320.
- Fully-enclosed housing prevents dirt & debris from obscuring the dot
- In contention for brightest and clearest glass on the market
- No glare in bright light
- Impressive waterproof rating down to 80 ft
- Optimal 3.5 MOA
- Change the battery without removing it
- 10-year warranty for personal use (2-year for pro or competitive use)
- Not the most aesthetically pleasing design
- Heavier than other models at 2.1 oz
- You might prefer a larger window
Whether you have fully-functioning young eyes or aging eyes, we’re confident that you’ve already landed on the best red dot for your Sig P320. We shared options to suit just about every budget and the top available sights to really take your optics to the highest level achievable. As we’re sure you already know, red dots are very user-friendly and perfect for all skill levels. No other sight helps you to acquire your target faster.
Finally, if we had to choose just one sight in this guide, we’d go with the Trijicon SRO because of its exceptional performance and clarity. After that, the Aimpoint Acro P-1 is just about on the same level. If you want to avoid buying additional parts, milling, or modifying your Sig, then stick with Leupold’s DPP or Sig’s Romeo1Pro.