Holosun 507c vs Holosun 507k

Holosun is a major name in pistol optics. They offer a range of sights for your pistol, and two of the most common are the Holosun 507c and the 507k. Let's take a closer look at these two so that you can decide which one is right for your gun.

Holosun 507c vs Holosun 507k

Before we make our recommendation for the best overall sight, you should understand the major points that we’ve evaluated the sights on. To place them on even footing for a side-by-side comparison, we’ve done an in-depth analysis of them in 7 different categories:

  • Price
  • Ease of use
  • Weight & physical size
  • Overall durability
  • Image quality
  • Battery life
  • Eye relief

Not only will we compare them, but we’ll take a look at exactly what similarities they share as well as the major differences between them. This way, if you’re looking for a pistol optic but only have a few factors that really matter, you can narrow down your choices quickly. In the end, we’ll lay out our recommendation for which is the better sight overall and why, knowing that either way, you’ll have the information you need to make an educated decision.

Price 

Prices on these sights fluctuate constantly, and while they generally move no more than a few bucks in either direction, no matter where you get them they will be relatively close to each other in price. With that in mind, the 507c will generally be anywhere from $10 to $20 more expensive than the 507k. 


This may not be a big difference to some, but for others, it can change their whole decision. Times are tough for a lot of folks right now, so we can completely understand if pricing is a factor that’s high on your list of considerations.

Ease of Use

Both sights are incredibly easy to mount, so no worries there. The windage and adjustment dials for the 507c are thoughtfully recessed into the housing so that accidental adjustments are nearly impossible. One thing to consider here is that the 507k does not have windage or elevation adjustment dials, and must be shimmed to zero.


Changing the battery in either one is a breeze, thanks to a slide-out battery tray located on the side of the sight. And both the 507k and 507c feature 12 daytime brightness settings and 2 night vision-compatible settings to adapt easily to any situation.

Weight and Size

This is one of the rare occasions where the sights have only a few similarities. They both have relatively small form factors, and light weights, however, the dimensions and the weights are different for both.


The 507k is 1.6” long, 0.98” wide, and 0.95” tall, which makes it the smaller of the two. The 507k weighs in at a single ounce, so not only is it small, but there’s little chance of it affecting your pistol’s balance in any significant way.


The 507c weighs 50% more at 1.5 ounces, and while still incredibly light, will have a more noticeable effect on handling. The size of the 507c is also more significant, being 1.78” long, 1.24” wide, and 1.54” tall. In addition, the 507c has a rounded top on the lens shroud, which makes it less conducive to concealment.

Durability

Holosun makes the housing for their sights from 7075 T6 aircraft-grade aluminum, which makes them highly durable, and able to stand up to just about anything you can throw at them. The only difference between the two is that since the 507k is slightly smaller, it will have a housing that is slightly thinner overall. 


For the vast majority of shooters, this won't have any bearing on usage, but if you intend to use it on a duty weapon you may need to take this small difference into account.

Image Quality

The image quality on both the 507k and the 507c is amazing. They both feature crystal clear glass without a heavy blueish tint on the glass from high-vis coatings. There is a slight coloring, but it’s so slight that you’ll eventually look right past it. 


Both models also feature the Holosun Multiple Reticle System, which gives you 3 options for a reticle. You can choose between a standard 2 MOA red dot, a 32 MOA ring reticle, or a ring & dot combo. The only difference between the two models is that the 507k only comes in red, while the 507c has a green reticle version and a red reticle version. 

Battery Life

Battery life is one of the things we love most about Holosun sights. They have astounding battery life when set to mid-range brightness, and unbelievable longevity when set lower. Both the 507c and the 507k use a single CR1632 battery, which provides a massive 50,000 hours set to brightness #6, equivalent to 5.7 years of continuous operation.


Both optics also have the Holosun Shake Awake feature, which turns the reticle off after a period of non-use, and back on again when the pistol is picked up. The primary difference in battery power between the two sights, however, is that the 507c includes a tiny solar panel on the top of the optic while the 507k doesn’t.


This solar panel can be used in a couple of different ways, both to supplement the battery life and to operate as a backup. When you’re shooting in a setting with sufficient lighting, you can simply switch the 507c to its solar setting to run the reticle from the panel instead of the battery. Additionally, if you’ve gone a good 6 years without changing your battery, there’s a good chance it may give up the ghost while you’re using it, in which case the solar panel can operate as a backup power source for your reticle, which can be a literal lifesaver.

Eye Relief

Eye relief isn’t generally too large of a concern with red dot or holographic sights, due to how they are intended to be used. Both the 507k and the 507c have infinite eye relief, allowing you to comfortably sight in while at arm's length, without needing any adjustment or grip compromise. This is essential to have a clear image during normal use.

Our Recommendation

When it comes down to it, both sights offer exceptional performance for a price that is more than reasonable. Not only are both sights made from aircraft-grade aluminum, giving them waterproof and shockproof construction, but they both have an incredibly clear image quality so no matter which you choose you don’t have to compromise on your lenses.


Both sights offer the Holosun Multiple Reticle System, which gives you three great options for your reticle. This reticle gets just about the same battery life regardless of which sight you view it on, or which of the 12 brightness settings you use, so you know that you won’t need to constantly feed it batteries. And while they both have the lifesaving Shake Awake feature, the 507c has a built-in solar panel to augment the battery.


These two sights are also only about $20 apart in pricing, and some shops will charge that much just for shipping, so for all intents and purposes, they cost the same. The biggest differences come in the size of the sights and their footprint on your pistol. This means that the best sight overall will depend largely on the gun it’s being mounted on. 


The best sight for those with a single-stack pistol or those that carry concealed will be the 507k because it has a slightly smaller form factor. If you open carry or will be mounting your optics to a double-stack pistol, the best option will be the 507c. The larger footprint will be a better fit for pistols with larger, wider frames.