Announced this year at SHOT, Holosun’s 507 Comp – for competition – optic made its way into mailboxes and retail stores back in May. With some time behind it, here are my thoughts so far.

One of the “secrets” to shooting a pistol-mounted optic is shifting your visual attention and focus from the front sight, whether it is the metal one at the end of the slide or the dot, to the target. Ideally, you look at what you need to hit on the threat or target and let the reticle appear there. Easier said than done. There have been times when the dot has drawn my eyes back to it.

Yes, there are ways to teach this, such as occluding (blocking) the optic, but I was looking for another way. Eventually, I found it.

Reticle Options

Enter Holosun’s 500 series optics and their multiple reticle system. They give the user the option of a single dot (like nearly all the others), a dot with a circle with tic marks at 3, 6, 9, and 12 (just like the EOTech reticle), and, finally, an empty 32 minute of angle (MOA) circle with those same tic marks.

All of the 507 Comp’s reticle options (photo courtesy of earlan357 @ pistol-forum)

Why was this a better mouse trap? The absence of the dot! On carbines, the EO Tech-style reticle is visually too busy for me. However, Holosun’s outer circle minus the dot lacks that visual overload. The circle makes it easier for me to look at the specific spot I want to hit while that reticle appears in my eye line as a reference.

If I found the lack of a distinct aiming point helped me, then I figured that was also making it easier for those I was teaching. So far, feedback has born that out. The empty circle makes the concept easier to grasp and perform.

The 507 Comp is directly mounted on an M&P 2.0 Compact – grip work by Boresight Solutions, slide cut by Fink’s Custom Gunsmithing, while the barrel and action enhancement parts are from Apex Tactical.

Holosun sights were on two of my M&P pistols – a 507K on my 4” Performance Center Shield and a 508T on an M&P Compact. The 507K stays set on the 32MOA circle-only reticle.

Fink’s Custom Gunsmithing at Gunsite cut the slide from an M&P 2.0 Compact for their 508T. That pistol has been a competition and teaching gun for me.

From L to R: C&H’s competition optic, the 507 Comp, and a 508T

Large Window

The 507 Comp looks to be their answer to Trijicon’s SRO as well as the new competition optic from C&H Precision. The first thing that stands out with all three of these is the window size. They are noticeably larger than other models – RMR, Acro, DPP, etc. While the SRO and the C&H competition both have round windows, the 507Comp has a larger, rectangular window.

Relative size and length, with the 507 Comp in the center. ETS’s new smoke-tinted magazine is on the right.

The window measures 1.1” x 0.87”. Generally rectangular in shape, it has a slightly curved top section. The window size makes the dot’s arrival in the eye line more consistent when working from a traditional ready position.

Holosun is reporting a 50,000-hour battery life for this model. As previous models have, it uses a 1632 battery. The housing is made of 7075 aluminum with “an industry standard footprint” – think Trijicon’s RMR/SRO. This model does not have the solar panel others have had. It also has their “Shake Awake” feature to re-activate the optic.

This optic comes with six reticle options: a stand-alone 2MOA dot and three open bottom circles, one 8MOA, another 20MOA, and finally 32MOA. Unlike its predecessors, the circles are neither closed nor do they have the tick marks at 3, 6, 9, and 12.

After cycling through those six, unsurprisingly, I choose the largest empty circle.

Looking at them from the front. Hopefully, a view you’ll only see here.


Holosun sent the 507 Comp to me in May. Prior to teaching a Pistol Mounted Optic instructor in early June, I had it installed on my M&P Compact. While the slide was cut for the RMR footprint and a Holosun optic had been mounted on it, the 507 Comp was a few thousandths of an inch longer than the previous optic. Regardless of the manufacturer, there can be variations in the dimensions of the same make/model optic bodies. It took a few passes with a file to get the body to fit the existing cut.

We installed it as I’ve described here before and, as of this writing, everything is staying tight.

Initially, I used the 507 Comp while teaching a pistol-mounted optics instructor class. It zeroed quickly. I fired two groups at 15 yards before checking, both were consistent in the location and size. I made my adjustments – up and left – before firing a third group which hit center and slightly low in X/10 rings of a PMO zero target. It held zero throughout the class.

Demonstrating Justin Dyal’s 5-Yard Round-Up with the 507 Comp

Every live fire demo I did in the class, whether a drill or a skill, was done with the M&P Compact and the 507 Comp combination.

Two hundred rounds at 10 and 15 yards – all misses are on me.

After the class, I took it out to the range a few more times to gather enough information to write this initial article.

Second Range Trip

Before the first trip, using the included Holosun tool, I checked it again for tightness. Both mounting screws were still tight as was the battery compartment. I fired 200 rounds of 9mm Estate 115gr ball ammunition. Drills started from either a low ready or a compressed high ready, at 10 & 15 yards, and included: singles, pairs, Fisher’s 1-6, failure drills, strong and weak hand-only work, as well as target tracking exercises. Apart from me letting some shots leak out of their intended impact areas, no issues were noted.

Ten rounds of Federal’s 147gr HST at ten yards, using the 32MOA circle. Those two? My fault

Third Session

In the second range session, I shot 260 rounds through it – 10 more rounds of 115gr ball, 240 rounds of mixed jacket hollow point duty rounds (that required 3 clicks up at 15 yards) – at 5 and 15 yards, and a final ten rounds of Federal 147gr HST at 10 yards.

I will be interested to see if its size adversely impacts one’s ability to conceal it.

While more time and rounds through the 507 Comp and M&P Compact combination are needed to say definitively, I think the 507Comp is making a good start.



Apex Tactical

Boresight Solutions

Federal Ammunition

Fink’s Gunsmithing