HOLOSUN HE403B-GR / HS403B 2 MOA Dot Micro Sight for Rifles - Shake-Awake Super LED Durable Waterproof Aluminum Sight with Multilayer Reflective Glass & 12 Brightness Settings - Red/Green Dot Options

Holosun has a well-deserved reputation for making quality red dot optics and the HS403B lives up to that reputation. It's attractive, very rugged, fairly easy to install and simple to operate. It has a wide range of adjustment for both windage and elevation, making it suitable for an equally wide range of firearms. The battery life is impressive and the "shake awake" auto-activation feature works exactly as advertised. Once zeroed, it holds zero without any issues. The red dot is crisp and easily visible. Its brighter settings are fully sufficient to make the dot visible in bright sunlight.My only complaint about this optic, and it's a very minor one, is that a basic 2 MOA red dot is the only reticle available. It would be nice to be able to select an "EOTech-style" reticle with a 2 MOA dot inside of a 65-68 MOA circle as an option. Given the sub-$200 price point for the HS403B, however, multiple reticle options is probably a bit much to ask. The simple red dot is sufficient for most shooting situations and the optic is, overall, an excellent bargain.

This is my second Holosun red dot. I bought a 507k x2 red dot for Sig 364xl, which fit perfectly and works great. Okay, on to this red dot. This was exactly what I needed, in the price point, for my .30 cal M1 carbine.It comes with a riser rail attachment, but I removed it and mounted it directly to my rail. The brightness can be adjusted up or down as needed and the glass is clear. I like where the buttons are placed and battery replacement is easy. I haven’t had it long, so I can not speak to battery life. I can tell you it is a solid and well made little sight. And I hear the owner is moving the company to the US for manufacturing in the near future.

UPDATE: Still solid, no issues whatsoever. Red dot looks just as new as the first day, haven’t had any problems losing my zero or with the battery. I am thinking of eventually buying an aimpoint t2 just because is one the best rds you can get but it comes at a higher price. For now this holosun will keep on doing!Have shot it about twice now and 200 rounds later. Pretty accurate and easy to zero in. Have no trouble hitting targets at 50 or 75 yards. The dot is very clear, even in harshlight where the sun is at its brightest. Its affordable but it doesn’t feel like a cheap rds. Although I want to upgrade to an eotech holographic sight, this rds has been very nice and enjoyable to shoot with. Currently shooting a DD m4v7.

I tried both the Sig Romeo5 and the Holosun 403b. After some testing and comparing, I ended up picking the Holosun over the Sig. Here's why:I like the co-witness of the Holosun more right out of the box (lower 1/3). This is more personal preference, but the Holosun comes right out of the box with the correct height mount for a lower 1/3 co-witness. The Sig comes out of the box with an absolute co-witness mount and you have to buy an extra mount if you want lower 1/3.The design of the Holosun is bit sleeker than the Sig. Because the Sig has the big battery cap on the side, it makes the Sig a little bit bulkier. The Holosun has a slick battery tray that pulls in and out of the side and isn't very noticeable.I like the function and feel of the Holosun top adjustment buttons more.They both come with easy windage/elevation adjustment knobs, so that's a plus for both of them.The glass and red dot on both of them are literally the exact same, so there is zero difference in that regard.The Romeo5 has two NV settings, but being that I'm now a civilian with no current NV capabilities and don't plan on having any in the near future, I most likely will never use them so they are useless for me.One thing I liked more about the Sig over the Holosun was the motion detection OFF feature. You can adjust the Holosun to turn off after 1 to 8 hours, the Sig comes with a non-adjustable 120 second turn off which I would prefer but it's not really that big of a deal since the battery life for both of these things are extensive.Hope that helps someone if they're looking at both and trying to decide which one to go with.

I have used this rds 3 times now and it performs very well. Ill be honest it is my first rds so i cant really compare it to other models. however, I avoided rds's for the longest time because i felt it was either junk, or aimpoint. and i didnt want to shell out hundreds of dollars for a non magnified optic.here lately i have found a need for a non magnified optic and decided that rds technology had improved enough for me to try it. the HS403b fit the bill very well, compact, light, long battery life, The price was decent, if not more than i wanted to spend, i was really comparing this to the sig romeo5, but this one had a better mount(1/3 over absolute) in my opinnion and i liked the auto on and off features.I did discover upon reading the manual a second time that you can adjust the auto off time. its default is 8 hrs, which to me seems much too long. it can be changed in 1 hr increments from 8-1. I have it set on 1 hr. Every time i pick up the rifle the dot is on, so im pretty happy with the way that works.the only grip/ improvement i would like to see would be a dot that adjsuts itself based on ambient light conditions. while the auto on works sometimes i have to adj the dot brightness up or down. of course i choose to purchase a model that doesn't have this feature at a lower price, holosun makes another model that does adj the dot but its a little more $$. so i cant really hold that against it.so far im liking it, its very quick on target, i was able to consistently ping a steel ram at 400 yards, so its not a precision scope, but it can be used very effectively out to much farther range than this type of sight is intended for.