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A couple weeks ago, Primary Arms sent me a Holosun 507C-X2 red dot sight, but with a unique DNA twist you can only get from Primary Arms. Instead of the usual red dot, circle, or red dot inside a circle, Holosun sights usually come with, Primary Arms sells them with an exclusive ACSS Vulcan reticle. Instead of a dot, the PA-upgraded Holosun displays a 10 MOA tall chevron in the middle of a huge 240 MOA circle.

A screenshot from the Primary Arms Holosun 507C-X2 w/ ACSS Vulcan manual.

Because the circle is so large, it doesn’t appear on the optic’s glass at all when you’ve got the pistol extended to shoot. When your eye is in the “eye box”, the circle is invisible. If you’ve practiced your presentations the way you should with pistol-mounted red dot sights and you’ve gotten to the point where you consistently see the dot or chevron every time, you’ll almost never see the circle.

But, we don’t live in an ideal world where you’ll always be able to get a perfect stance, grip, and alignment as you do on the range. You might have to shoot from an unusual position with distractions, injuries, and other complications that make for an imperfect alignment and not seeing the dot.

When that happens, you’ll need to start the process of searching for your dot, refocusing on iron sights, or using your thumb to conjure up the magic dot again. But, with the ACSS Vulcan reticle, you won’t have to do that.

Another screenshot from the manual.

When your alignment is off, the Vulcan reticle’s outer ring will show up on the screen. The human brain is very good at processing circles and filling in the blanks, so you naturally know what way you need to adjust to get your reticle back, based on the curvature of the portion of the circle that’s in your display.

Without having to think about it, you’ll be back on the chevron and ready to quickly make a shot.

In my testing, including dry fire practice until my arms hurt several times, as well as a couple hundred live fire rounds on the range, the circle-and-chevron system works as advertised. Any time I didn’t get the chevron on the glass, my brain automatically corrected and got me back to the dot with minimal delay.

The only word of caution I’d give to anyone making this their first red dot is that you don’t want to rely on the circle. It’s a great tool for getting it right faster in difficult situations, but you don’t want to draw, see the edge of the circle, and correct every time you shoot.

Like any pistol RDS, you need to train to make the reticle show up in the glass without relying on the circle.

You never know when you might encounter a dilophosaur out in the desert (or, a movie poster with one that someone else left up after shooting). Sadly, it’s difficult to get a good shot of the reticle on a phone camera. But, I’m confident I’d fare better than Dennis Nedry with this setup!

But Can It Handle 10mm?

I’ve become a devotee of 10mm this year. I used to be a big fan of .40 S&W, even after most of the rest of the defensive shooting world moved on and re-embraced some old Austro-German pistol round. Instead, I’ve gone the other way and went for the full centimeter.

Yes, .40 S&W has a reputation for beating up pistols, especially frames originally designed for 9mm. And 10mm is just a really spicy .40. So, hanging the Holosun on a gun chambered in 10mm is an endurance test for a red dot sight.

Ten millimeter is hardly the suitcase nuke stuffed into brass that some people think it is, but if the optic can hang out on my 10mm M&P without trouble, it can probably handle just about any pistol slide you’ll mount it on.

The optic mounted on my M&P 10mm slide, including some messy witness marks I made with a paint pen.

I am happy to report that with proper mounting (degreasing, thread locker, witness marks as described here), the  Holosun HS507C-X2 has gone the first couple hundred rounds with no problems whatsoever. I’ll follow up in future posts to see how the Primary Arms Holosun does as it gets more rounds down range.

Pinpoint Accuracy, Even Beyond Point Blank

When I zeroed the optic, I was surprised at what an advantage the chevron is over a red dot. Instead of having a 3+ MOA dot on the glass, you can zero the gun to the tip of the chevron. That means you’re actually able to zero down to a smaller point, making for a more precise zero.

Using a rested position at ten yards, I was able to have nearly all shots touching my aim point on cardboard.

With a zero at 10 yards and shooting full-power 10mm 180gr Gold Dots (from manufacturers like Underwood and Fenix, or handloads), the maximum point-blank range of the gun on a three-inch target goes out to around 80 yards. But with knowledge of the trajectory and knowing that the chevron is 10 MOA tall, you can use it to quickly estimate holdovers for 100+ yards (or 200 to 300 yards with rifle calibers).

Primary Arms gives several suggested zeros for popular pistol and rifle calibers, but you can cook up your own recipes with a ballistics calculator.

Using this system, I was able to score hits on a 4″ steel target at 100 yards from a kneeling position, but need to work on this more using paper targets to tune things in further. Hits out to 150 yards on a man-sized target aren’t unrealistic at all if you have solid fundamentals.

For now, so far so good with the Holosun 507C-X2 riding on a 10mm handgun. And the ACSS reticle is a big plus.

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  1. Whoa hitting four inch steel at a hundred yards with a pistol!
    I have heard great things about red dot sights for pistols as a game changer.
    This is a red dot with a traffic controller to get you to line up better.
    I am intrigued by the chevron allowing you to take those long shots.
    I am old and fat so the 45 is fine by me. I am also OCD, so I think what are the most common rounds I could get in an emergency. 9 or 45 both are so engrained that they should be easy to come by. Although these days ammo in general is like trying to find national treasure.

  2. “…a suitcase nuke stuffed into brass…”

    Somehow, that resonates and sticks in my head. I like it, suitable to chat up any favored cartridge. I may start using that in my chats with my buddies.

    Thx, Jennifer. 🙂

    • What are you talking about? I’ve had this reticle since shortly after it was released, and I have yet to change the battery… Seems to be on par with other red dots I have had (RMR, previous Holosun’s, etc.)

      • With the Vulcan reticle on it only has about a 5,000 battery life. With just the chevron on it gets about 20,000-30,000.

        • The reticle is not “always on”. It comes on when the gun is moved. It’s longevity in practice has been the same as my other optics.

  3. Been trying to find one for months to put on my TP9 compact and test for next carry gun. Quick question though, red or green? Thoughts? I do have astigmatism.

    • Interesting if quite pricey. One wonder’s if I could convince a DA I needed to shoot a criminal from 300 feet away using it. Especially in ILL annoy. Looks good irregardless…

    • Gman, I have astigmatism as well, any dot easily doubles in size and flares towards the 4:00 position but red noticeably flares more than green for me and the green stands out significantly better. I have a holosun with a finer 8moa circle only reticle which I quite like but do wish it came in green.

      • Depending on how bad the astigmatism etched glass, holographic, and prism type sights may be the starting point. May not matter for pistol distances re defense but situation and individual eyes would make that decision. And for anything past 200m I had to use iron sights (focused the dot a bit with the rear sight) or an acog for the sight to be of any use with m-4/249.

        • Safe, yeah thanks, I have way too much crap; an optic on everything, easily over a doz, including about four prisms plus another on order and yes, they are def the answer. I should’ve mentioned that to Gman, maybe your reply was meant for him, I’m sure he’ll see it here.

        • Rider my bad looks like it defaulted to you on reply and any advice on prisms under 600 in either of our markets?

    • Works fantastic for those of us with astigamatism! I’ve looked through a plethora of micro red dots and they all bloom, blur, squiggle or some other crazy thing on me. But this one doesn’t do any of that. It is bright and clear. I prefer green to the red. For larger red dots I’ve gone to Prismatic ones because they don’t bloom or blur.

    • “Quick question though, red or green? Thoughts?”

      The human eye is more sensitive to green than red light, so unless the brightness level is different between the 2, green should ‘pop’ more than red…

  4. I think Jennifer may have been confusing the 10mm with the world renowned and encircling 6.5 Creedmore cartridge. Or is the suitcase sized one the smaller version? If so, might that not actually be relegated to the lesser known .65 Creedless round, as whispered about in hushed tones by media experts?

    • Not sure what you are referring to, but 10mm was dropped by the FBI for having too much recoil (though it’s not as bad as alleged) and it’s quite capable of hitting targets at long distances because it’s a very high velocity round, for a pistol cartridge.

      • He’s obviously referring to the smaller of the nuclear-like cartridges. It’s extremely fast and powerful due to being a necked down .9 mm.

      • Jeremy, was a silly reply to Haz up top; my comments are going into the trash bin for unknown reasons and Dan is looking into it. I think maybe Big Brother has just had enough of my crap 😉.

  5. I think Jennifer may have been confusing the 10mm with the world renowned and encircling 6.5 Creedmore cartridge. Or is the suitcase sized one the smaller version? If so, might that not actually be relegated to the lesser known .65 Creedless round, as whispered about in hushed tones by media experts?

  6. Now make a smol boi version! I would upgrade the daily carry sights for this, as long as it still had all the same features.

  7. May want to head over to Lucky Gunner Lounge and check out Chris Baker’s post on his holosun optic failure before you buy one. Losing zero is a common issue with their red dot sights.

    • I’ve got thousands of rounds through a half doz diff models all on .45 pistols plus a couple more on two sksss and not an issue with any.

  8. 3moa dot is as large as i can tolerate. being able to see more field, less target blocked with the little carat is appealing.
    4″ plate at 150yds? yow!
    10yds? give me a wishbone and a blue tip and i’ll be on paper in two shots.

  9. This is absolutely horrific to use if you have any time behind a red dot.

    Spend a week dry firing and practicing your draws. It’s not hard to get used to finding the dot. Present, prep, pinky pressure.

  10. Anyone who needs an extended circle outside the viewing area in order to “find their dot”, shouldn’t be carrying a dot until they’ve trained in proper presentation. Then, this silly little circle purpose vanishes and you’re left with a stupid little inverted V aiming point that your eyes will struggle to focus on in a threat-based scenario.

    Good for plinking, sure. Good for self-defense? No.

    • Ah, the old “you train it out, until when you raise the gun the dot is already in the field of view” argument. We used to call that “point shooting.”

      Me, when I’ve tried red dots on handguns, I find myself tilting the gun this way and that, trying to find the microscopic sliver of an angle from which the dot is visible, for far, far, far too long. When I think about having to do that while someone’s trying to kill me, it doesn’t make me feel warm and fuzzy. I’ll stick with the irons. If I can’t see the front sight, I raise the muzzle a bit and there it is, no problem, no batteries required, either. But then I’m an old fart.

      I’m not so old that I can’t see the utility and the virtue of a red dot sight on a long gun, like a flattop AR. Put your nose to the charging handle and the dot’s just right there, so long as you have a consistent cheek weld. I tried to put my cheek on my M&P’s slide and the slide came back and chipped a tooth.

      As for the specific optic being reviewed, it’s described as having a large ring around the central aiming point, to give a visual cue to tell you where the aiming point is if the presentation isn’t absolutely perfect. To me this seems like a step in the right direction. Maybe I would feel more enthusiastic about red dots on handguns if they all worked this way. Though I’m still concerned about battery life. I’m concerned about betting my life on a sight that’s basically just bits of aluminum and plastic with a thin glass window, too, concerned that it could get bumped or damaged in a struggle–defensive handgun uses typically take place at very close quarters–and wonder how durable something so small and light, that has to be as small and light as possible so it doesn’t keep the slide from cycling correctly, can really be.

      I know there are illuminated optics with what they call a “Shake Awake” feature. The sight has motion sensors that turn it off automatically after a few minutes without any motion, then turn it back on if the gun moves. Will this work on a carry gun, or is it only suitable for a home defense gun that won’t be touched or jostled or moved until the moment it’s in use? The motion sensors would have to be sensitive enough and reliable enough that they’d always turn the sight on when you draw, but not turn it on and run the battery down while you’re just walking around. Can they do that? Would that work? Could you put a sight like this on a rifle and carry it on patrol, then have it turn on automatically when you raise it to your shoulder? It’s another idea that sounds really good but I have no idea how well it actually works in the real world.

      For that matter, how much flexibility in eye relief is there in prismatic optics? Could someone make a non-magnifying, very compact 1x prismatic optic for handgun applications? It might be easier to focus on for those of us who have astigmatism, and an etched glass reticle wouldn’t become completely invisible when the batteries died, though I suppose you’d need good lighting conditions to see it without illumination. Some prismatic optics are really tough, really well constructed, maybe more so than the typical handgun red dot. But those tend to be really heavy for their size. Would it be too heavy to mount on a slide? Would the extra mass cause the slide not to cycle properly? I’m just asking. I’m not rejecting the idea of optics on a pistol completely. I’m not sure everything about the idea is ready for prime time, though.

  11. Please let me know the total brightness levels of Holosun 507C-X2. Does this Holosun 507C-X2 come with any auto brightness adjustment feature?

  12. This seemed like an interesting concept and definitely useful on some red dots, especially the smaller ones. I bought the Holosun 509 with this reticle and immediately noticed the closed emitter housing can easily be used like the oversized circle, making this ACSS Vulcan reticle redundant.

    So the ACSS Vulcan is only useful on open emitter optics…

  13. LOL, first this version of the 507c is anything but new. Second, the battery life is fantastic. Third, one of mine has held zero flawlessly for over 5K rounds of 9mm. Another one of mine has held zero flawlessly for right around 15K rounds of 22LR on a TX-22 Competition. Lastly, this is hands down the best reticle on the market right now.
    Pro Tip: degrease your slide thoroughly prior to installing your dot. Second, Blue Loctite and a FAT Wrench for proper torque. Third, keep a few back up batteries in your range bag. These can be changed very quickly with the side tray design. Last, suppressor height sights.
    Someone asked red or green? Red by a mile for me.
    The 9mm I have this mounted on is my 3 gun pistol and has been through heck and back. Holding up like a champ. The TX-22 competition is used for steel challenge and plinking. If you’re looking for a dot for a more narrow pistol, the 6MOA 407K is my favorite. Yeah, I’m a Holosun and Dimitri Vision fan.

    • PS…..I think it’s Jennifer?? I forgot to say, amazing marksmanship. A 4″ steel at 100 is pretty impressive for my old eye. Also super nice group there.

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