Holosun 507 Comp vs 407 Comp vs 507C: What’s the Difference?

All four of these Holosun dots share the Trijicon RMR footprint, so the real choice is window size and reticle. The 407C and 507C use the small 0.91 x 0.63 inch window, with a 2 MOA dot on the 407C and a dot plus 32 MOA circle on the 507C, while the 407 Comp and 507 Comp use a 1.1 x 0.87 inch window with either a 6 MOA dot or the full dot and 8, 20 and 32 MOA circle system. Pick a 407C or 507C for a carry compact, and a Comp for a full-size or competition pistol.

Holosun 407C vs 507C vs 407 Comp vs 507 Comp at a Glance

	407C X2	507C X2	407 Comp	507 Comp
Reticle	2 MOA dot	2 MOA dot, 32 MOA circle, or both	6 MOA dot	2 MOA dot plus 8, 20 or 32 MOA circles (8 combinations)
Window	0.91 x 0.63 in	0.91 x 0.63 in	1.1 x 0.87 in	1.1 x 0.87 in
Housing	1.78 x 1.15 x 1.15 in	1.78 x 1.15 x 1.15 in	1.8 x 1.3 x 1.3 in	1.8 x 1.3 x 1.3 in
Weight	1.5 oz	1.5 oz	1.7 oz	1.7 oz
Footprint	Trijicon RMR	Trijicon RMR	Trijicon RMR	Trijicon RMR
MSRP (2026)	$288	$365	Not listed here	$435
Best fit	Compact and full-size carry pistols	Carry pistols, shotguns	Full-size and competition pistols	Full-size, duty and competition pistols

Shared by all four: 7075 T6 aluminum housing, IP67 water resistance, side-loading CR1632 battery, Shake Awake and 1 MOA adjustments. For the rest of the lineup, see our best Holosun red dots guide.

Holosun Footprint Guide: What Fits Where

All three optics use the Trijicon RMR footprint, the most common pistol optic pattern. That has a few practical results.

• RMR-cut slides take any of the three directly.
• Factory optics-ready pistols with plate systems, such as Glock MOS, need the RMR plate.
• Rifles and shotguns use RMR-pattern mounts, which is why our 507C review ran the optic on a Benelli M4 on a low mount.
• Slimline pistols such as the Glock 43X MOS and SIG P365 use the smaller RMSc pattern. An RMSc to RMR adapter plate can work, but the 507 Comp in particular is much wider than those slides and the plates add height. We would not put a 507 Comp on a micro-compact.

Because the 407C, 507C and 507 Comp share a footprint, you can move up to the Comp later without changing your slide cut. Check that your rear sight still co-witnesses, since the Comp’s taller window changes the sight picture.

Holosun 407C X2: The Simple Dot

The 407C X2 is the 507C’s housing and window with only a 2 MOA dot. It is the right pick if you want a clean, precise aiming point and do not care about a circle. It has Solar Failsafe, Shake Awake, a side battery tray so you do not have to remove the optic to change batteries, and a lock mode to prevent accidental button presses.

The older 407 CO, which used an 8 MOA donut in the same housing, is discontinued. Our reviewer considered it one of the best reticles Holosun made, which is part of why the 507 Comp’s bigger circles appeal to him.

Holosun 507C X2: Dot, Circle or Both

The 507C uses the same housing and window as the 407C but adds Holosun’s Multi Reticle System: a 2 MOA dot, a 32 MOA circle, or the circle and dot together. In our 507C review, the 32 MOA circle proved useful on a shotgun, where it showed exactly where buckshot patterns landed at home-defense distances. The optic ran more than a thousand rounds of full-power buckshot without flickering.

The 507C offers 10 daylight and 2 night vision brightness settings. Holosun’s glass has a slight blue tint, which some shooters notice and most stop seeing after a few range trips. Post-lawsuit X2 models use smaller side buttons than early 507Cs. For a beginner’s view of running one on a pistol, see transitioning to pistol red dots with the 507C ACSS Vulcan.

Holosun 507 Comp: Bigger Window, More Reticles

The 507 Comp is the reason this page exists. It keeps the RMR footprint but gives you a 1.1 x 0.87 inch window, compared with 0.91 x 0.63 inch on the 507C. That works out to about 0.96 square inches versus about 0.57, a window just under 70 percent larger. The window is about as wide as a SIG Romeo3 XL and about as tall as a Trijicon SRO.

The Competition Reticle System

The Comp’s Competition Reticle System gives you a 2 MOA dot and 8, 20 and 32 MOA circles. You can run the dot alone, any circle alone, or any circle with the dot, for 8 options. Hold the minus button for a couple of seconds to switch.

Our reviewer tested the 507 Comp in competition on a Glock 45 MOS for more than six months. On stages with targets past 20 yards, he ran the 8 MOA circle and dot. On close, fast stages, he ran the 20 MOA circle and dot. In head-to-head testing, he was generally faster on target, on follow-up shots and in transitions with the 507 Comp than with the 407 CO, even when using only the 8 MOA circle. The bigger window keeps the dot in view under recoil and when your draw is not perfectly aligned.

You Do Not Need a Tiny Dot

A 10 MOA dot covers about 5 inches at 50 yards, and a USPSA A zone is 6 inches wide. Our reviewer shot USPSA for more than a decade with a 10 MOA dot, including 50 yard standards stages. Bigger reticles are faster to find, and for most pistol shooting they are still precise enough.

507 Comp Gripes

Two complaints from our testing. All three circles have a small gap at the 6 o’clock position, and our reviewer would prefer closed circles. He would also prefer a larger 4 to 6 MOA dot over the 2 MOA dot. If a bigger dot alone is what you want, Holosun’s 407 Comp uses the same large window with a 6 MOA dot. Our 2024 review counted fewer brightness settings on the Comp, but Holosun’s current spec sheet lists 12 for the 507 Comp (8 daylight and 4 night vision), the same total as the 507C X2 (10 daylight and 2 night vision). The difference is the split, with more night vision settings on the Comp.

507 Comp Specs

• Reticle: 2 MOA dot with 8, 20 and 32 MOA circles
• Footprint: Trijicon RMR
• Window: 1.1 x 0.87 inches
• Housing: 1.8 x 1.3 x 1.3 inches
• Weight: 1.7 ounces
• Housing material: 7075 T6 aluminum
• Adjustment: 1 MOA per click, plus or minus 30 MOA of travel
• Water resistance: IP67
• Battery life: up to 50,000 hours
• Price: $435 MSRP (2026), the same MSRP as when we reviewed it in 2024, when street prices were about $369 in 2024

Which Holosun Should You Buy?

Buy the 407C if you want the simplest, most precise dot on a compact or full-size carry pistol.

Buy the 507C if you want the same small housing with the option of a fast 32 MOA circle, which also works well on a shotgun.

Buy the 507 Comp if you shoot a full-size pistol, run competition, or simply want the biggest window you can get on an RMR cut. It carries fine on a Glock 17, 19 or 45 sized gun, but it is too wide for a micro-compact.

For more Holosun options, see our reviews of the 507 ProMax, the 407K, the AEMS the SCS and the titanium 3X magnifier, plus our best pistol red dots guide.

Holosun 407C vs 507C vs 507 Comp FAQ

What footprint is the Holosun 507 Comp?

The 507 Comp uses the Trijicon RMR footprint, the same as the 407C and 507C. It fits RMR-cut slides and RMR plates directly.

What is the difference between the 507C and 507 Comp?

The 507 Comp has a window just under 70 percent larger, more reticle options with 8, 20 and 32 MOA circles, and a slightly larger, 0.2 ounce heavier housing. Both use the RMR footprint.

What is the difference between the 407C and 507C?

The 407C has only a 2 MOA dot. The 507C adds a 32 MOA circle that can be used alone or with the dot. The housing, window and footprint are the same.

Will the 507 Comp fit a SIG P365 or Glock 43X?

Not directly. Those slides use the smaller RMSc pattern. An adapter plate can make it fit, but the Comp is much wider than those slides and we do not recommend it.

Is the 507 Comp good for concealed carry?

On a full-size or compact pistol, yes. Our reviewer carried a Glock 45 with the 507 Comp and found the housing did not feel much bigger than a 507C.

Is the 407 Comp the same as the 507 Comp?

The 407 Comp uses the same large window and RMR footprint but has a single 6 MOA dot instead of the multi-reticle system.