The Holosun 507K P365XL – The SIG P365’s Best Red Dot

Holosun 507k p365xl

It’s almost like they were born to be together.


The SIG P365 is easily the most influential firearm built in the last decade. This micro-compact 9mm found a way to shove double-stack capacity into a gun the size of a single stack. SIG has since innovated and pushed the firearm forward, and the P365 XL model came complete with a slide cut for an optic. I built a little thing I call the P365X, which is a standard frame with an XL slide. Along the way, I went optic’s shopping, and over and over again, I only found one that was near-universally praised. That optic is the Holosun 507K.

Sig P365 Red Dot

The Holosun 507k p365xl is a micro-optic and one of the few currently on the market for guns this size. The Holosun 507K is the little brother to the 507C and seems primed to dominate the micro-optic market. Before we dive into why you’re likely asking why would I attach a red dot to a concealed carry pistol.

Red Dots Rule with Holosun 507k P365XL

That’s the answer, up there, the heading. It’s because red dots rule. Red dots on handguns have proven to be an excellent addition. A red dot on a handgun grants you the same benefits a red dot does on a rifle.

Best Red Dot for P365x

The Holosun 507k p365xl eliminates the need to align sights, which increases your speed. The red dot is simple and easy to see and allows you to engage at greater distances with better accuracy. Lastly, red dots are designed to allow shooters to focus on the target instead of the sights. That’s much more natural than concentrating on the sights. Swords, spears, clubs, and fists are all target focus weapons, and traditional firearm sights defy what’s natural.

Red dots aren’t for everyone and admittedly take some retraining to utilize. That retraining is well worth it, at least in my humble opinion.

Why The 507K is Perfect for the P365

The 507K is chock full of features, and most of them benefit the P365 XL directly. The 507K uses the RSMc footprint, which comes stock on the P365 XL. The optic is ultra-small and weighs only about an ounce, so weight and bulk aren’t an issue. The 507K sits very low on the gun and reduces height where it can.

Holosun 507k p365xl

The rear end of the 507K has a small notch designed to be used as an improvised rear sight. The SIG P365 XL’s rear sight is removed when you attach n optic, so the little notch is a welcome addition. The optic also sits low enough to see the front sight and use the rear notch in case the optic fails.

Holosun 507k p365xl
Notice the notch as a rear sight

Red dots like the 507K eliminate the issues with sight radius on small handguns. Red dots allow you to shoot a small pistol almost as accurately as a full-sized duty handgun.

The Holosun 507K p365xl Inside and Out

The Holosun 507k p365xl is not just an excellent P365 optic, but a good optic in general. The 507K runs off of small CR1632 and runs for 50K hours at setting six. There are 12 total settings, with 2 being night vision compatible and ten being daylight compatible. The battery is a side-loading design, so there is no need to remove the optic to swap batteries.

The controls are two small buttons located on the side of the optic. These little buttons make swapping brightness levels, turning the optic on and off, and even changing reticles easy.

Oh yeah, did I mention you can swap reticles? Yep, the Holosun 507k p365xl is fitted with three reticles. Users get a 2 MOA dot, a 32 MOA circle, and a combination of the circle and dot. The larger reticles are more manageable for those with astigmatism to use and appear clearer than just a dot. The bigger reticle is also fantastic for close range, speed-based shooting. It’s easy to find, easy to track, and perfect for the role a concealed carry gun serves.

Holosun 507k p365xl

The Holosun 507k p365xl  is a brilliant design that is perfectly suited for modern carry guns. The little fella fits perfectly with the P365 and delivers unbeatable performance. Speed, precision, and focus are all improved by the addition of a red dot. The Holosun 507K just happens to fit the P365 like a well-made glove.

The Holosun 507k p365xl also happens to fit perfectly with a wide variety of CrossBreed holsters. This includes my personal favorite, the DropSlide, and Reckoning holsters.


medical gear, med kit, SIG P365, air gun, Accomplice Mag Carrier, concealed carrier, concealed carry, responsibly armed, home security, home defense, weapon-mounted light, Streamlight, tlr-7, Streamlight tlr-7, self-defense, lds, light defender series, home defense firearms, tlr-1, tlr-6, Streamlight products

Travis Pike is a former Marine Machine gunner who served with 2nd Bn 2nd Marines for 5 years. He deployed in 2009 to Afghanistan and again in 2011 with the 22nd MEU(SOC) during a record-setting 11 months at sea. Travis has trained with the Romanian Army, the Spanish Marines, the Emirate Marines, and the Afghan National Army.

He serves as an NRA certified pistol instructor and pursues a variety of firearms-based hobbies.


You may also enjoy these popular articles:
SIG, P365, P320, CrossBreed Holsters, IWB, OWB, concealed carry, SIG SAUER, SIG P365   Home Security, Self-Defense, CrossBreed Holsters, security, protection    IWB, OWB, Holsters, CrossBreed Holsters, cool weather, concealed carry, open carry, IWB Holsters, OWB Holsters

Follow us on Social Media:
Facebook, share, article, crossbreed holsters, handguns, concealed carry, hybrid holsters, blog    Twitter, share article, share, article, crossbreed holsters, handguns, concealed carry, hybrid holsters, blog  

CrossBreed Holsters, concealed carry, IWB, OWB, best holster, hybrid holsters, holster, IWB Holster, OWB Holster, CrossBreed, holsters made in America, made in the USA,
©MTC Holsters, LLC and CrossBreed Holsters Blog, 2021.
Unauthorized use and/or duplication of this material without express and written permission from this site’s author and/or owner is strictly prohibited. Excerpts and links may be used, provided that full and clear credit is given to Travis Pike and the CrossBreed Blog with appropriate and specific direction to the original content.

17 thoughts on “The Holosun 507K P365XL – The SIG P365’s Best Red Dot”

  1. I have a Sig P365 and would like to add the Holosun 507K as in this video from CrossBreed (Travis Pike). He used a slide from the P365XL and I would like to know where to purchase the slide to make this conversion. Any advise would be appreciated.

    1. You can buy all the slide in the P365X and the P365XL version directly from Sig Sauer’s website, that is what I did.

  2. The Holosun 507K fits very well on the Sig P365XL. The only thing I personally recommend is to get the new ACSS model. The ACSS model offers that large ring to guide your eye back to the reticle if it’s lost in the window.

  3. Cort Viesselman

    Does the Holosun 507K come with screws so that I don’t need anything else to replace the sight on my P365 SAS. I am sorry to say I can’t find that sight under many conditions.

Leave a Comment

Your email address will not be published. Required fields are marked *