Holosun HS 507C X2 | ACSS Vulcan Reticle

HS507C review
January 10, 2024  
Categories: Guns

When I first moved to a red dot sight on a handgun, the options for a pistol red dot sight durable enough to trust my life on for duty as a Deputy Sheriff was a short list of one: the RMR type 2. There simply were no other compact versions that compared when it came to battery life and durability. Sure, you could mount a full-sized Aimpoint onto a frame mount, but that would tend to be a bit bulky for law enforcement work.

Holosun 507C (the X2 version with ACSS reticle).

This article will be covering the Holosun 507C (X2 version with ACSS reticle), but first, you gotta know how I got there. This model optic is one of many available online at Primary Arms

Once I was ready to make the transition, I mounted an RMR type 2 on my gun and went running and gunning. For two years, the rig was as reliable as the sunrise, and then… poof. Dead battery. The first real failure of a system I KNEW was going to happen because….

Batteries die.

Trijicon RMR Type 2 Reflex Sight.

Trijicon RMR Type 2 Reflex Sight. (Not my optic, not me, just here for reference.) My first RDS was one of these. 

I loaded up a backup Glock with plain old iron sights and went to work. I dropped off said Glock at my buddy Ed’s Gunshop of Magic, and he quickly had me back in service. Now, there’s nothing saying I couldn’t replace the battery myself, But I had to go to work and didn’t have the time to sit down and clean off the marking paint and make absolutely sure I didn’t strip a screw, then replace the battery and remount the whole sight before letting the Loctite dry before taking it back to the range to verify the zero (an absolute necessity when it’s a duty weapon). All in all. I was down a couple of days.

Several years of experience running a slide-mounted micro red dot on a pistol had me running a pistol as well as I had ever run one. I opted to go through firearms instructor school with a bone stock Iron sighted Glock. The reason was simple. No one at my agency or working as a LEO locally was carrying a red dot sighted pistol except me. If it was a personal skills class, I’d have run my RDS setup, but I was there to work on teaching, particularly to my agency, so I didn’t cheat. I shot well in the class and returned to teach at my agency and others.

My first go at running qualifications for my agency had me doing the expected coaching and retraining for officers whose skills fell off from lack of practice in the previous year. I found that sometimes handing them my RDS-sighted gun would help me diagnose a problem or even sometimes prove to a shooter that they were capable. Other times, they were interested in the RDS gun, so I’d just let them try it out. Every single shooter walked away wanting to put an RDS on their Glock.

During these years, the Georgia State Patrol, an agency I do a lot of work with, transitioned (2020-2023) from the iron-sighted Glock 17 to a Glock 45 Gen 5 running a Trijicon SRS and a weapon-mounted light. I’ve talked with more than a few Troopers whose reactions are all 100% positive when it comes to the transition. This has many agencies in my area authorizing officers to carry personally owned weapons equipped with RDS and other agencies gearing up to issue RDS-sighted guns. This is just the first of the entire wave of officers in my area transitioning to the new standard. 

This wave of transition has officers (and citizens) coming to their local agency firearms instructors and the instructors they know to get advice about what to buy, how to set it up, and, if we are lucky, coming to get some instruction and training running their new gear. I have helped several pick out their optics and tactical gear, set it up, and get to running and gunning with it.

The HS507C X2

One of the first was a patrol officer who had already picked out his dot and his gun. It was a Glock 45 with a Holosun 507 he already had mounted on the gun. Getting him up and running was as simple as teaching him to target focus versus years of training front sight focus, teaching him to aim his hands low and his eyes at the target to overcome the natural issue of pointing high, and assuring him that the high level of the wobble of the dot versus iron sights is just the difference in the sighting systems. He was quick to pick it up, and after getting past the newness of it, he had no interest in going back.

Holosun HS 507C X2

Another early student in the art of the Red Dot was a nice lady in her late 50s. Bet that was unexpected. Here is a civilian, older, woman, who is not really a shooter, who is prepping herself for self-reliance.  She had the gun already purchased, a Walther PDP-F. She is a small lady who chose her gun based on two important points for her. Can she get a proper grip that allows her smaller hands to reach the trigger, and can she rack the slide? The Walther meets both of those and was set up for both a light and an RDS. 

She asked me to help equip her gun, and after trying my Grey Ghost running an RMR, she liked the dot system enough that she told her husband (a gun guy) to make it happen. I ordered the sight I’ve come to recommend for new RDS shooters, The Holosun HS 507C X2 with Primary Arms proprietary Vulcan ACSS reticle.

RDS on a Grey Ghost Precision Combat Pistol.

RDS on the Grey Ghost Precision Combat Pistol in question.

Now, she could have any red dot. The price is not the issue. The issue is what works best. for. her. She needed something tough like we all do. The Holosun fits. She needs a sight that requires little to no maintenance. The Holosun has a LONG battery life and an easy system for replacement (a convenient tray slides the li ion battery out). Lastly, she needs a sighting system that, as a less practiced shooter with some vision issues, works for her. This is where the Primary Arms Vulcan ACSS sets the system out front from others.

Holosun HS 507C X2 mounted on a handgun.

This Holosun HS 507C X2 is mounted on a Glock 19 MOS.

Once we got her gun bolted up, I got her loaded up and shooting. We kept it practical for her applications. We made sure she could run the gun. She found the added bonus leverage the RDS gives in racking the slide a HUGE advantage for her.  Shooting across the room and across the yard distances had her getting respectable groups. She had the Vulcan reticle to help her. She didn’t have the old “find the dot game” going on, as the Vulcan reticle has a chevron as the aiming point and a genius OVERSIZED large outer reference circle around it.


When I say oversized, I mean exactly that. The circle is so big you don’t see it until you are so far off that you can’t see the chevron. Then you see a piece of the outer circle, which acts as an intuitive video game-esque indicator of where the chevron (aiming point) is. HUGE ADVANTAGE for a new-to-red dot-shooter. She could self-adjust without coaching as the equipment was so well designed.

This self-correcting is, in my opinion, an order of magnitude easier to learn, leading to the students picking up the draw to first shot faster. AND if you don’t like it, you have the option to turn the circle off.

Holosun Technologies HS507C X2 ACSS
  • Battery Life: 10,001-25,000 Hours (Solar Failsafe)
  • Battery Type: cr1632 battery (3V Lithium Coin)
  • Brightness: 12 settings
  • Click value: 1 MOA
  • Finish: Hardcoat Anodized
  • Mount capability: Trijicon RMR, Holosun 407C/507C footprint
  • Night vision compatibility: yes
  • Reticle: Red Dot Sight ACSS multiple reticle system
  • *Does not ship with a Picatinny mount

Then the real advantage of any red dot kicked in. I had her start moving and shooting. Just a step to the left or right, but this is where most new shooters completely break down. Adding movement does that. It’s as simple as processing power. Your brain has limited horsepower, so the less power it takes to run your gun, the better. Dots do that. They simplify the process of aiming by allowing you to superimpose a dot over your target and take a target focus

ACSS Vulcan Reticle

The ACSS Vulcan is a patent-pending reticle with a center chevron surrounded by a large (but counterintuitively non-intrusive) outer reference circle intended to help “guide” the shooter’s eyes toward the aiming point. The outer circle doesn’t become visible until you can no longer see the chevron. This provides a mechanism for the shooter to self-coach and self-adjust until, with repetition, you’re not chasing the dot. You’re going straight to target acquisition.

The ACSS Vulcan Reticle is a revolutionary approach to mini reflex sights, improving user agility through a ‘heads-up’ target acquisition. Under duress, standard mini-reflex reticles can be lost without proper sight alignment. With the ACSS Vulcan reticle, users always know the relative location of their aiming point, allowing for quick correction and improved accuracy on target.  Holosun Optics

Vulcan Reticle System Diagram

The ACSS Vulcan reticle features a 10 MOA high chevron aiming point surrounded by a 250 MOA circle. This circle indicates the relative position of the chevron when the sight is off-center. At an average arm’s length (27”), the ACSS Vulcan will only show its chevron when properly aligned. If the sight is canted, the outer ring comes into view, guiding the user back to the center.


This eliminates the ‘searching’ problem on traditional dot reticles, enabling faster sight acquisition. Iron sights require, for precision, that you fight your body’s natural want to target or threat focus and focus through the rear sight, find and focus on the front sight while working with a blurry target. Fewer steps equal less processing power.



I can sit most capable people down and have them ringing steel at a distance with static targets and sitting still, but the second I introduce movement, most (not all) people’s brains seem to hit overload. It’s just the limit of most people’s processing power. Now we can train and practice to get past that point. AND WE SHOULD, BUT we can also start a new shooter on an EASIER sighting system.

DRS Thermal Pro Optic from Holosun next to Golden Trigger Award.

Look out for our article about Holosun winning the Golden Trigger Award for Best of Show!

We got her to take a step left or right, and after the first couple of tries, she easily picked it up and went back to making acceptable hits on the targets at realistic distances.  This is huge. Getting off the X is the first part of GUNFIGHTING vs shooting. Shooting is punching; gunfighting is MMA. Getting a new shooter to this point is our first goal, no matter the platform. I just have to get you past the point where you can run the gun before I introduce movement and try to teach you about angles and tactics.


I can get you past working on focus for sight picture especially in odd positions, to moving and shooting and thinking about angles and tactics with less practice and training. 

A red dot for her added the advantage of being so much easier for her to rack the slide. For a small lady with a weaker grip, this could have been the deal breaker. A red dot made it easier for her to work with her body and use a threat or target focus as opposed to having to dedicate many hours of effort and dry and live fire to overcome. The red dot gave her a fine aiming point which contributed to her getting better groups.

The wonderful ACSS Vulcan reticle had her back to the chevron, naturally using as little brain power as possible. Lastly, the red dot versus iron sights had her using less brain power to achieve the same hits. In that visit and multiple sessions afterward, she showed that the RIGHT red dot for her on the right gun – the right fun for here – paid dividends in her performance.

The most recent adventure in setting up a red dot was setting up a brother, Chris, with a gun to run for a training experiment. Chris is an experienced officer with 20+ years on the job and a hobby shooter who easily clears his qualifications at work. He runs red dots on rifles and has shot plenty of red dots on pistols; he just hadn’t made the transition to a red dot on his carry-and-duty gun. 

With all of the advantages it gives, everyone has to be asking, WHY doesn’t EVERY officer carry an RDS-equipped pistol?  First is Agency restrictions. Some agencies don’t allow officers to carry personally owned firearms. The second is cost.

Cost seems as simple as saying a red dot costs $350; then there is your cost. Not even close. First is the cost of the gun. You have to make sure the gun is at least equal to your issued gun. Same or similar model to start. A quick breakdown is:

  • Glock 45 MOS —-$650
  • Suppressor Height sights–  $100
  • Holosun Primary Arms ACSS—–$350
  • Weapon light——–$150 to $300+
  • Proper DUTY Holster—- $200 +
  • Proper Concealment Holster— $100

Total—-$1550 and up

For an officer Making around $50K a year, this is 2 weeks’ pay plus, especially if you account for taxes. This is the real reason almost every officer isn’t carrying an RDS-equipped gun: the cost. A Holosun Optics reflex sight at $350 vs a $600 Aimpoint Acro P2 may be the difference for the individual officer. Remember, I’m not talking about the absolute top-tier gear. I’m suggesting gear I have seen work for people who are NEW to a pistol-mounted RDS.

 M&P 2.0 Metal with Holosun P.ID and HS507C-X2

A S&W M&P Metal wearing a Holosun HS 507C X2. [Greg Skaz]

We set Chris up with an MOS Glock and a Holosun 507 with the Primary Arms Vulcan ACSS reticle. His agency was on board; we set up the sights, he already had a weapon light, he ordered the holsters and waited. And waited. And waited. When the holster arrived, it was the wrong one. EBAY refused a refund. Company re-shipped. Again, the wrong one. Lesson learned. For a holster, go to a company you KNOW. Safariland provided me with a great duty holster for my setup that works perfectly for his. 

Now that he was set up, we ran the quals. ZERO problems qualifying expert, but he did see the normal issues good iron sight shooters see. Going to a target focus, worry about red dot wobble and the hunt the dot game. ALL of which were easy for him to overcome through effective coaching, his extensive experience as a shooter, and the ACSS reticle.

Chris also brought to my attention that for a shooter with slight astigmatism, the ACSS reticles and chevron help find the precision aiming point versus a dot, which can turn into a star or a slash with astigmatism.

Now I am seeing local agencies following GSP’s move to red dots so much so that I expect the local police academies to start allowing cadets to use red dots. It’s inevitable. The move is happening. While it may not be the move for YOU, it doesn’t hurt to give it a try if you can find someone who has a gun set up already.

I expect in the next 5 years, we see 50% of law enforcement transitioned, and in the next 5 years, after that, we move to 85% of agencies nationwide. The holdouts will be smaller agencies that are still hanging onto the same old guns. 

EXOS Glock 19 compensator from Faxon Firearms

This will lead to more and more of the public carrying red dots, and that will lead to more advancements in both the equipment and the training we will see for it. Which leads me to the next steps and problems. As a nation, we have gotten away from teaching officers GUNFIGHTING because it was all we could do to teach them basic marksmanship with dwindling budgets, less dedicated time towards training, and other liability-driven training, which has pushed gunfighting to the back of the bus.

We need to push to do better by our officers. Equip yourself as you choose.

A big thanks to Primary Arms. I have been a customer of theirs for a while. My SWAT rifle has a Holosun AEMS, I have several officers I have setup with Holosun products usually purchased from Primary Arms, I have several of their products I use, and they provided a Holosun HS 507C X2 ACSS (the Vulcan ACSS reticle) for this article and others. Their service is TOP NOTCH, and every time I have ordered from them, and my friends have ordered from them, the products arrive BEFORE expected. The only thing better than great top-notch gear is TOP NOTCH GEAR with great customer service, and this is exactly what Primary Arms delivers.


HS507C X2 for Sale


If Primary Arms doesn’t have it (try there first), here are some other options.

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Jake Bush

Jake Bush

About the Author

Jake is a LEO down Georgia-Florida way. Jake describes himself thusly: I’m a small town deputy sheriff. I’m not special forces, I’m not SWAT, I’m not metro with LAPD or a homicide detective with the NYPD. I’m basically a problem solver. Everyday I handle calls from the mundane car in the roadway, to the worst calls for service, and everything in between. What I write will be from this perspective because I have no other. I hope something I write helps you.” Jake has been a night-shifter for years, and a cop for over a decade and a half. Despite an uncanny resemblance to Peter Griffin (especially when he’s in his uniform shirt), we really like him. In fact, we count ourselves lucky to have him aboard.


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