We get a lot of questions about the Mepro M21 reticles; what they are designed for and which is best for a particular purpose. Here is a quick overview of the different reticle styles:
Everyone is familiar with dots, of course. The large dot (5.5 MOA) is a bit faster to acquire, the small dot (4.3 MOA) is more precise, but might be a little slower to acquire in the toughest light conditions. Maybe because I am a sniper, I prefer the smaller, precise dot.
This reticle is absolutely the best for CQB fighting. It can be used as one large dot for close, fast shooting. For more precise shooting, the small center dot is used. It can be used to range targets and for holdovers. It is very good for general purpose use. It can obscure certain sized targets at certain ranges, which annoys some people who are trying to shoot small groups on a paper target on the range, but this is not an issue for combat use. It is very resistant to washout, since it is larger and easier to pick up.
The bullseye reticle is also available in the MOR because of customer demand, but I feel that the dot reticle is the best option for the MOR.
This reticle is similar to the Bullseye in usefulness, except that the point of impact is left open. This means that the reticle will never obscure the point of impact. It was designed specifically to have the advantages of the bullseye but also be used for precision shots with a magnifier. It can be used to range targets and for precise holdovers. It is the preferred reticle for a combination of CQB and use with a magnifier.
This is a great all-around reticle. It can be used as a large dot for close-in CQB fighting, yet zeroed to the point of the triangle for precision shooting. By zeroing the point of impact just over the tip of the triangle, the reticle won’t obscure a target. Shooters who want to shoot small groups at the range especially like the Triangle reticle. It can be used to range targets and for holdovers.
I have all of the reticle styles and use all of them. I have a number of Bullseye reticles, my home defense carbine has an Open X reticle, My Beowulf bear protection carbine has a triangle, and my IDF carbine clone has a 4.3 MOA dot reticle.