MEPROLIGHT MEPRO M21 Day and Night Self Illuminated 1X Fiber Optics and tritium Powered Reflex red dot with Bullseye, dot, Triangle and X reticles, Passive no batteris Glow on Reticle

I've only used this once, but so far I'm very impressed with it. The triangle reticle offers the quick pickup of a red dot for shorter distances, with the precision of a iron sight for longer distances. I zeroed it at 100 yards using the top tip of the triangle as the point of impact. In that regard, it reminds me of an old Mauser front sight, it works quite well. Shots can be quickly placed in a center-mass sized target at 50 yards or closer by using the whole triangle as a large red-dot. This sight is built like a brick schit-house, you would probably have to go to great lengths to damage it. It's nice to not have to worry about batteries since it runs on fiber-optic in the daylight and tritium in the dark. It's also nice not to have to turn it on or off, it's always "on". The one issue that often comes up when reading reviews about the M21 is reticle wash-out. If you're in a dark place (inside a dark room for instance) and you're aiming into a bright place (out the window of the dark room into the daylight) it can wash out, depending on how bright it is outside and how dark it is inside. This really isn't a problem for me, however. I shoot at an outdoor range that has a roof over the firing line. Shooting from the shade to the bright sunlight wasn't a problem at all, the reticle was bright and crisp. About the only bad things I can say about this sight are the slight possibility of reticle washout and it's weight, it is heavy at nearly a pound. But these aren't very big problems to me, I feel the positives far outweigh the negatives of this sight. This is a fantastic relfex sight for the AR platform, and would be right at home on many other tactical-type rifle platforms as well.

Comparison of the two premier tritium powered 1x optics.I own both the Acog reflex and M21 now and I have to say it's a very tough choice which I would chose over the other.Main problem with both:Washout- these are powered with fiber optics and tritium. When it's dark, the tritium illuminates and reflects of the lens. When it is bright the fiber optics collect the light and then reflect it off the glass. So more light, a brighter reticle. Less light, a dimmer one.When shooting from a shaded or darker area, this is where the issue occurs. It is collecting little to no light and not producing a bright reticle. So if you were to aim the optic out to a brighter area, the reticle will disappear (washout). You are unable to see it and aim.Best at combating washout?Winner: Acog ReflexI own the bullseye model of the M21 and amber dot of the Acog. The color in the Acog is much richer and darker. The M21 is much lighter. In situations where the dot would wash out on the M21, the Acog was still visible. And if I took it to an extreme and pointed both at a light and covered the fiber optics up... Not an issue for the Acog***main let down of M21***No Polarizing Lens!!!The Acog comes with a lens that lets you adjust the opaqueness of the lens (like transitioning glasses). If it is bright out and you're shooting from a poorly lit area, you can use this lens to darken it and... You can clearly see the reticle. The fiber optics for the Acog sit at the front of it while the M21 is situated on top. So the type of light that you are shooting into will affect the reticle more on the Acog while the light your are shooting from will affect the M21 more.I have not been able to find a polaraizing lens for the M21. There is a washout remover that is available ( but requires batteries) which defeats the purpose of this type of optic.The lack of this lens is about enough for me to choose the Acog over the M21 even though I would say the M21 is superior in almost every other area. Build, feel, reticle, size, & bang for your buck.The M21 comes with a QD mount where you will have to spend another $100 for that on the Acog. The metal has a nice finish compared to the rougher texture on the Acog.The reticle type on the Bullseye model is great. Like if the Acog and Eotech had a baby. It's big and can be used for rapid acquisition where the amber dot Eotech will take some practice picking up quickly.Both are built like a tank and are in one solid piece. I do not doubt there ruggedness and would feel safe taking either one with me in the case of fall out.I have also had range time with the micro aimpoints (which are about $300 more) and would still chose either one of these over any red dot. Do. It for get both of these are still used today in combat and you won't go wrong with purchasing them.***side note***I also bought the MX3 magnifier that's goes with the M21.I would chose the Eotech G33 magnifier. The M21's lens has a teal hue that is ver pronounced with the use of a magnifier.

I've used an Aimpoint Comp ML2 on my Springfield Socom 16 for a few years now, but have been looking for a 1x optic that will allow me to shoot more accurately out to 200+ yards. I read about Meprolight's 12 moa triangle reticle and decided to try it out. I am very impressed by this scope. Triangle is clear and sharp, no visual artifacts. By placing target on the tip of the triangle I've been shooting well, out to 200+ yards. Windage and elevation adjustments are 1 moa, firm clicks, easy to use. The viewing window is large and allows for both-eyes-open shooting. The glass is tinted a gentle green, which both accentuates the orange triangle and is restful to the eye. I like the sight picture better than my Aimpoint.Before purchasing, I read reviews that mentioned the possibility of "reticle washout." I shoot at a gun range where the benches are in a very shaded spot, and shooting out into bright sunshine has worked perfectly well. If you aim into a Very bright light, of course you lose reticle intensity, but that holds true for all red dots.Optic is well made, rugged, comes with quick release mount (easily adjusted), no batteries needed - I love it. Highly recommend. Comes with a neoprene cover. And it's fully half the price of a new Trijicon reflex sight.Note: In order for this optic to fit on my Springfield Socom 16, I needed to modify the scout rail. For the M21 quick release mount to fit, I had to file off the ridge on the scout rail closest to the muzzle. Not a problem; the scout mount is aluminum and easy to file. It does not interfere with attaching other optics including my Aimpoint. The M21's rear bolt fits in the notch just behind the blank in the middle of the scout scope rail, and the forward bolt fits in the space cleared by filing off the foremost ridge.Hope this is helpful to those who own a Socom 16.