Holosun HS503BU Micro Red Dot Sight

The Holosun HS503BU 2 MOA Red Dot Sight is housed in a durable, aluminum housing that has a unique U-shape design that protects the windage and elevation turrets on two sides. Parallax free with an unlimited field of view, these Red Dot Sights by Holosun have an incredible battery life of up to 5 years on a single CR2032 battery located internally and accessible through the internal tray on the side of the optic. The Holosun HS503BU 65 MOA Circle Dot Scope features Shake Awake motion sensor technology that turns the optic on whenever movement is sensed and automatically shuts back off once the movement has subsided. For a reliable, versatile sight that will increase your accuracy and speed up your target acquisition, choose the Holosun HS503BU Parallax Free Red Dot/Circle Sight.

95.75 /100
  • Design


  • Performance


  • Value for money


  • Feature


Features of Holosun HS503BU 65 MOA Circle Dot Scope, 28Y-RD-HS503BU:

  • Shake Awake - Motion based on and off
  • 2 MOA dot & 65 MOA Circle
  • Reduced training time and ammunition
  • Unlimited field of view
  • Parallax-free with unlimited eye relief
  • Durable and reliable construction

1-Holosun HS503BU Micro Red Dot Sight
2-Holosun HS503BU Micro Red Dot Sight
3-Holosun HS503BU Micro Red Dot Sight
4-Holosun HS503BU Micro Red Dot Sight
5-Holosun HS503BU Micro Red Dot Sight
6-Holosun HS503BU Micro Red Dot Sight
7-Holosun HS503BU Micro Red Dot Sight
8-Holosun HS503BU Micro Red Dot Sight
9-Holosun HS503BU Micro Red Dot Sight
10-Holosun HS503BU Micro Red Dot Sight
11-Holosun HS503BU Micro Red Dot Sight

  • PROS
  • Ease of use
  • battery life
  • Price & quality
  • Cost effective, well built, lots of options
  • All of the ablove about the optic
  • good price and made well
  • ultimate value
  • Quailty, clarity, features
  • Circle Dot
  • Inexpensive and feature packed
  • Small cheap and reliable
  • easy to use
  • low price
  • good clarity
  • Auto off feature
  • Crisp, clear dot. Circle/dot.
  • Battery life.
  • Well made. Value.
  • Batteries last forever
  • solid construction
  • clear, crisp reticle
  • wide range of brightness levels
  • easy-access controls
  • CONS
  • fiddly battery compartment
  • adjustment dials mushy
  • Mount is questionable
  • Magnifying bad at long range
  • buy more ammo/wife less mad
  • I would like a larger front objective lens
  • Battery access
  • No rubber bump cover
  • Wind and elevation not labled
  • Made in China
  • Not waterproof.
  • discrepancy in stated battery life
  • auto-shutoff is rather long (at 10 mins)

Enjoyed this article? Stay informed by joining our newsletter!

Junius - Add Reply

Works as advertised. Easy to use, consistent, lightweight. The circle dot reticle is outstanding. No issues mounting or shooting with ease on my 7.62X39 AR SBR. After several trips to the range it appears to be an excellent value at $175. Enough said, buy one!

You must be logged in to post a comment.
Manuela - Add Reply

This red dot sight is great. Quality build and materials at least for my intended usage. Put it on a ksg build and it works great. One warning is that if you are planning to swap out the mount to another T1 style mount this red dot will sit about a 1/4 inch higher than a T1 due to the battery tray being underneath the actual scope. This means a T1 mount for lower 1/3 cowitness will not cowitness at all and an absolute cowitness mount will show in the lower 1/3 so plan for that. I learned the hard way. �

You must be logged in to post a comment.
Garnett - Add Reply

Had this on my Ar before I purchased my ACOG. This is a great little sight. Auto on function with 5 year battery life for under 200!!! It has very clear glass and the option to switch between the 65 moa circle and the 2 moa dot is great.

You must be logged in to post a comment.
Fernando - Add Reply

I like this red dot a lot. It was my first one I’ve purchased. Right out of the gate I knew how to set it up and attach it and was able to figure out all the settings with ease having no hands on ever before on any type of red dot sight. It was very user friendly. The dot itself is nice and crisp and small. I love how it has the options of just a single red dot and/or a larger one around it at the same time. Makes it very well equipped for quick target acquisition in close range. I haven’t done any roughness testing or water testing on this sight nor will I ever. There’s no reason to abuse it out of the box like some people try to do to see if it’s worth it. I don’t shoot 1000 rounds plus a week out of this gun but I shoot it just every so often. I have it sighted in at 100 yards and that’s good for me. I have it when I need it and that’s that. I don’t believe I’ll find myself in a depth of water holding this gun to where I couldn’t keep it out of the water and mist and rain isn’t going to ruin this sight. I also don’t think I’ll ever be throwing it in the mud and sand or running over it with a vehicle lol. If you want a good, easy, and reliable sight for an average guy and an average shooter that you can afford, well this is perfect. If your all about home defense I think this sight can work too. If your over the top and want to wake up for your own “fire watch” every night for an hour and patrol your home for intruders cause you think your gonna get robbed every night, wel... Read More...

You must be logged in to post a comment.
Rafael - Add Reply

This Holosun was recently purchased for my MP5. I've always been a fan of military grade red dots , and this Holosun is a first for me. At first, I was skeptical about the low price but decided to buy one to give it a go anyway. I was drawn by the long battery life and the fact that I could choose between having a circle dot style reticle and the red dot sight. When I received the unit, I was immediately blown away by the sharpness of the reticle and the clarity of the window / glass compared to the more expensive optics I am used to. The quality of the red dot far exceeded my expectations as I suffer from astigmatism and finding a red dot that doesn't smear is not an easy task. But the dot on the Holosun is bright and crisp making the unit very easy to zero. Other thumbs up for this unit includes turret caps that have a little knob to adjust zero built in, included bases that have a high and low mount, simple button layouts and an incredible battery life. Are there flaws with this red dot? Sure. I'm not a fan of the battery compartment. The screws securing it are small and fiddly, so changing batteries in the field is probably not an option. It would be nice if they had printed the direction of the red dot adjustment on the casing instead of the caps covering the turret. The unit could be more rugged, but given the price, it doesn't really matter. Despite these flaws, I've since become a fan of Holosun and would definitely be buying more of their red dots in future.

You must be logged in to post a comment.
Alf - Add Reply

This really cant be beat in the price range / features. Zeroed in about 3-4 shots. The circle dot is a nice feature as well as the auto on. The quality is there! And optics planet had this to me in just few days. Excellent service !! More Holosun products are in my future

You must be logged in to post a comment.
Eino - Add Reply

I just recently purchased this Optic and I couldn't be happier! The reticles are very clear and crisp as well as the glass. The sight itself is very durable and I can see myself having this sight for a very long time. I would strongly recommend. Can't be the price either!

You must be logged in to post a comment.
Joshua - Add Reply

After running almost every red dot on the market I decided to take a chance on the Holosun for a budget AR pistol build. To my surprise the quality is outstanding, the glass is extremely clear, and has little to no glare. The shake awake feature is really nice not to mention the 50,000 hour battery life. If I had to find anything wrong I would say that the mount could be better but it can be replaced with a Aimpoint t2 mount very easily. If you want Aimpoint quality for a third of the cost this is the sight for you.

You must be logged in to post a comment.
Edgar - Add Reply

Great optic ! Crystal clear,very sleek and durable! Would recommend this to anyone looking for a red dot . My brother purchased a halo son for his A.R. 15 build and he is pleased with the optic as well .

You must be logged in to post a comment.
Tyree - Add Reply

The optic was easy enough to install. The optics works fine! It’s not a scope, so Don’t buy this if you are looking for downrange magnification. But it works great for close range options. Would recommend it to a friend

You must be logged in to post a comment.
Jeromy - Add Reply

Are you going to battle ISIS in the Middle East? If the answer is "no" buy this red dot.... $157 bucks and free shipping... plus better features (shake awake, battery life) than EOTECH... HOLOSUN iis the leader here... and by the way the reticle looks the same when your on target... Save your cash! Spend the $300 you saved and go buy ammo and practice, practice, practice shooting... (the more expensive red dots won't make you a better shooter fyi).... the 503BU works just as well and your wife gets 1/2 as mad when you buy it. I use it for monthly competitions... I noticed lots of other guys have the same red dot and I haven't heard one complaint about the HOLOSUN... with a lifetime warranty this is a no brainer... and when you finally get deployed you'll be happy you had the extra cash for all that practice ammo... HOLOSUN BIG THUMBS UP!!!

You must be logged in to post a comment.
Cicero - Add Reply

I have several Holosun red dot optics and am very pleased with them. For their price, quality and battery life, you can’t find a better budget optic. The mounts could be a little stronger but mine are used for mild to moderate conditions and have held up well.

You must be logged in to post a comment.
Fredrick - Add Reply

The circle dot combination gives the shooter a variety of ranging options for close-in work. This sight is great whenever a quick shot is called for with "good enough" shot placement accuracy is acceptable. Yet, the 2 MOA dot allows for accurate shot placement below 100 yds.. The verticle and horizontal hash marks help with weapon orientation, while sighting at range, so your bullet drop is not skewed. Brightness is as to be expected, as is clarity. "Motion On" feature works well, but the battery life claim.... well it's to soon to tell. I haven't drop kicked it yet, nor do I plan too, anytime soon to test durability. I suspect it would pass with flying colors based on inspecting the build quality. NOTE: THE FRONT LENS IS CANTED ON PURPOSE. IT'S NORMAL! Bottom line, for the price, you will love this little sight.

You must be logged in to post a comment.
Demarco - Add Reply

I replaced my Bushnell TRS25 with this sight. The Bushnell, while good, was not bright enough to be seen in full sunlight. The Holosun absolutely does not have that problem. It glows like the sun. The controls are easy to use and the adjustment covers have built in screw driver heads for adjusting with. The circle dot sets this optic above other sights. It makes the dot very quick to pick up. The only down side is the "tray" you have to unscrew to insert the battery. They provide a spare tray, so it must be problematic. Given the stated battery life, I don't expect this will be a problem very often. I liked the first one I bought so much that I bought a second one.

You must be logged in to post a comment.
Ambrose - Add Reply

I own sights from Eotech, Aimpoint, Trijicon, Meprolight and several others and this thing keeps up with the best of them. It’s price is great and the features surpass most of the above brands. I wish Holosun would get into magnified optics. I would to see what those would look like. Even a simple 3x magnifier would be nice to see from them.

You must be logged in to post a comment.
Norberto - Add Reply

Time will tell how this red dot holds up, but from what I've gathered these are well made. When it comes to simplicity, size, function and form this red dot is hard to beat for the price. Even if this were a $400 red dot, it would still be a viable option. Optic clarity and the crispness of the dot is perfect. The Circle dot option is brilliant, I love the option of being able to switch between the two. Three things I would like to see done differently personally, but don't reflect my overall happiness with the product. -Holosun logo is bright, would like to see a darker paint used. -I wish the windage and elevation adjustments were printed on the turrets themselves, although having it printed on the caps works well enough. -I would greatly prefer if the brightness setting were on the left side of the red dot. This would allow the user to adjust the brightness easier. Holding the rifle with a magwell grip, you could use your thumb to adjust the brightness without breaking form.

You must be logged in to post a comment.
Faustino - Add Reply

I have been looking for a good red dot for a long time now but couldn't and didn't want to pay the price tag that went a long with a lot of them. I put this one on and started shooting. Now I haven't had this thru as many rounds as my others, but I see this thing holding up. Great construction and I am just really a huge fan. I will be putting one of these on some of my other rifles

You must be logged in to post a comment.
Jack - Add Reply

Love the simplicity of an Aimpoint, but price makes it impossible, then try the Holosun HS503BU. This is a simple, set and forget sight like the Aimpoint, at less than a quarter of the price. At medium settings, the battery will last 50K hours, and runs off a standard CR2032 (readily available). They sight has an auto power down feature to save battery life, however when you pick it back up, it will turn on to the last setting used. The dot is crisp and handles a magnifier well. It is rugged enough for my truck gun, and holds zero well if you mount it on a quick detach mount. You can't beat this sight for the money, and I much prefer it over my Vortex Sparc AR.

You must be logged in to post a comment.
Dee - Add Reply

Bought this on a great sale by optics Planet. Just mounted it it in an ADM qd mount and put 100 rds down range. BTW if you do buy the ADM 1/3rd co-witness mount it won't actually co-witness because the battery being in the base of the optic makes the base slightly taller than a T1. I don't care about co-witness however so I like the ADM qd mount. I love it so far and as long as it holds up that won't change.

You must be logged in to post a comment.
Presley - Add Reply

So far so good with the Holosun. Currently have the Holosun HS503BU mounted on my scorpion evo. Holding its zero nicely. Looks good and functions even better. My favorite part is that when you leave the gun alone it will turn off but as soon as you grab it the sight turns back on. I was hesitant at first but I would buy another one for a different gun.

You must be logged in to post a comment.
Jayce - Add Reply

I just completed work to install a free-float handguard on my AR-15. I cut down the front sight to make a low profile gas block, and installed the Holosun sight. I am very pleased with the results. First use gave 1.5 moa at 100 yds with budget ammo. Great sight at a great price.

You must be logged in to post a comment.
Nils - Add Reply

I've had this sight for about eight months now and switched it between two different AR 15's and a Ruger 10/22. Each time the sight stayed true. It hold zero very well. The auto on and off is a great feature. With out movement sight turns off in about 10 mins.

You must be logged in to post a comment.
Alexandre - Add Reply

I’ve been so impressed with this sight I’ve bought another one. I have mounted on an AK using an Ultimak rail. Works great. Dot is very crisp with more than enough brightness in any lighting conditions. Not sure I can do without the circle/dot feature after experiencing it with this sight. Both have functioned flawlessly. Only wish it was waterproof.

You must be logged in to post a comment.
Kurtis - Add Reply

I was looking for a affordable durable red dot for my AR pistol and this was the best I have found. High quality, ten brightness settings, and comes with two mounts, overall a awesome product at a great price.

You must be logged in to post a comment.
Hunter - Add Reply

I really liked everything about the sight, including the price. Though after about fifty rounds the front glass came loose. Optics Planet was very helpful and offered a full refund or exchange. I opted to try the same sight again. So we'll have to see. Three so far on the sight, I would give OP a five though.

You must be logged in to post a comment.
Jon - Add Reply

I just got my HS503BU for use on my Kel-Tec KSG. I actually got it to replace my HS503C, which is basically the same optic but with different features. Switching from the C to the BU on my home defense shotgun because the auto-adjusted brightness of the C changes the brightness based on the ambient lighting directly above you, which often makes it too dim when looking into bright areas, or too bright when looking into dark areas. Also having to manually switch it on is a drawback when you need to react quickly. The BU solves those issues for me. As stated in the title, the battery life stated on both Optic Planet's and HoloSun's websites is "up to 50,000 hours," and the box states "50,000 hours with the Dot/20,000 hours with the Circle Dot." However the manual of the optic states that "due to use of new LED technology, the optic can be operated for up to 10,000 hours." It doesn't specify any difference based on which reticle you use. On a home defense gun that will likely be sitting still most of the time, that's not so big a deal, but it will probably be on most of the time while you're moving around with it, or while it's in your car. The super-long battery life was a pretty big selling point, and now I find out it might be up to 5x shorter than advertised. Kind of a bummer. Besides that, the build quality is excellent, it feels sturdy, the shake-awake feature works as advertised, and there are plenty of brightness levels to find exactly what you need. When it activates a... Read More...

You must be logged in to post a comment.

You must be logged in to post a comment.

Related Articles