3 MOA vs 6 MOA RED DOT – Which Sight is Better?


So many shooters today are investing in red dot in red dot sights for their pistols and firearms. The 3 MOA and 6 MOA are very popular reticle sizes. Both the 3 MOA nad 6 MOA red dot are guaranteed to fulfill all your shooting needs.

If you are interested in achieving a rapid target acquisition, investing in a pistol that is fitted with a 3 MOA red dot or a 6 MOA is a great choice. The Burris Fastfire 3 is a high-quality 3 MOA Red Dot sight designed with great features and the Vortex Viper 6 MOA Red Dot sight is of very high standards.

When it comes to selecting your most preferable sight, it is vital that you consider different factors.  The quality, reliability and the material are some of the factors that must be put into consideration before you make your purchase. Both the Fastfire 3 model as well as the Viper model are designed with very similar features and are a favorite amongst many shooters.

What is the difference between a 3 MOA red dot and a 6 MOA red dot 

Burris Fastfire 3
Viper Red Dot
The sight is light in weight and very reliable. The Burris model places a clear red dot onto your target providing shooters with a fast precision and speed advantage. You can use it as a basic optic or you can mount it on top of your sight.
This red dot optic has a very low profile. This feature makes it an excellent choice for pistols that come with cut-out slides. The Viper Red Dot has a low height making it work well with iron sights. Working with this red dot is not hard and firing at your target can happen very quickly.
Dot Size
3 MOA Dot
6 MOA Dot
0.9 oz
2.1 oz
Material Type

The 3 MOA and 6 MOA – How do they compare

Size of the Reticle 

Vortex Viper is designed with a 6 MOA while the Burris Fastfire 3 comes with a 3 MOA option. The difference between both MOA is quite large and shooters can easily notice this as soon as they have made use of both optics. In this case, a smaller dot is preferable. Quickly firing at a moving target with a handgun or a pistol is not as easy as it seems. 6 MOA optic is more advantageous especially when it comes to all types of tactical applications. The 6 MOA dot provides users with a clear and crisp target acquisition function when compared toa 3 MOA dot. This proves that it is better to focus and work with a 6 MOA red dot than a 3 MOA red dot. 

Weight and the Size 

Vortex Viper Red Dot, as well as the Fastfire 3, are both lights in weight. They have a slight weight difference of only 0.4 ounces. According to very many shooters as well as experts, a slight difference even of only 0.1 ounces can greatly influence your performance while on the field. To ensure that users can enjoy a maximum level of applicability, the Burris Fastfire must be placed on to Picatinny rails. Mounting the Fastfire onto these rails increases the total weight, however, users should not use the optic without attaching it onto the Picatinny rails. Both models measure 1.9 inches which is great as this means they are both small in size. When it comes to the weight, the Viper Red Dot is a better option than the Fastfire as shooters prefer to work with a model that is lighter in weight. 

Quality of the Image 

For many years the Burris Fastfire 3 continues to attract users because of the quality of produced images. The Vortex Viper is not a pioneer model like the Fastfire, however, it still performs well in the market attracting numerous shooters. The lens diameter of the Vortex Viper is much wider than the Fastfire. This amazing quality proves that the field of view of the Vortex Viper is wider than the Fastfire. The images of the Vortex Viper is are a clear indication that this optic is a better option than the Burris Fastfire 3.

 3 MOA vs 6 MOA RED DOT – A Comparison

Burris Fastfire 3 

Burris 300235 Fastfire III No Mount 3 MOA Sight (Black)
  • Material Type: Aluminum
  • Sport Type: Hunting
  • 3 MOA Dot Reticle
  • Tool-less wind age and elevation adjustments

The Burris Fastfire 3 is strong and durable yet one of the most affordable options in today’s market. It has a very nice design and ideal glass. Shooters are assured that they will be provided with a very wide field of  view. With just one single button, you can toggle between 4 different settings. This is the off button as well as 3 other brightness settings. All the brightness options are ideal for shooters who would like to make use of night vision optics. You can also make use of the auto-adjustment feature to turn on the sight or turn it off.

Battery life of the fast fire model can last up to 5 years. Fastfire III also has an automatic turn off function. It operates after 9 hours. The surface area of the sight is great at ensuring that the battery will not die, even if you do not turn it off. This sight works well with numerous rifles and shotguns and it is an ideal for any type of shooting competition or hunting activity.


  • Brightness features as well as the shut off function operate automatically and can run up to 9 hours.
  • It is one of the most affordable sights in the market
  • The sight is light in weight.


  • Many users have complained that the on and off switch is not as strong and can easily disintegrate and break.

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Vortex Viper Red Dot

Vortex Optics Viper Red Dot Sight - 6 MOA Dot
  • The Viper Red Dot Sight has a super low-profile making it perfect for handguns with cut-out slides.
  • The Viper's low height allows it to co-witness with iron sights and the 6 MOA dot is easy to pick up and...
  • The fully multi-coated, ultra-clear lens offers a wide, unobstructed field of view while Armortek...
  • Hard anodized finish- highly durable low-glare matte finish. 1 MOA windage and elevation adjustments move...

This red dot has a very low-profile design and it is specifically made for pistols and handguns that come with cut-outs on the slide. The G MOA feature ensures that you can benefit from a quick target acquisition function even when positioned at a close or medium range. Its size of this sight does not allow you to mount it on any kind of height pistol sight that is suppressed. Vortex Viper is designed with a multi-coated lens and this adds to the light transmission. It also reduces the clarity giving users a chance to enjoy a great view.

Vortex Viper also has a nice matte finish and a very low glare. It is impervious to external factors such as fog, snow, and water. The unit remains safe from dangerous climatic conditions. Optics controls and functions are designed on the right-hand side. The Viper red dot makes use of a CR 2031 battery model. To replace this battery, the sight must be detached.


  • It is very compact
  • Compatible with a tall pistol sight
  • Designed with a very low profile
  • Great fit for pistols


  • Shooters can only use the single dot choice provided
  • It makes use of a CR-1632 battery that is not easily accessible.

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Both the Burris Fast fire 3 and the Viper Red dot are light in weight and very compact. They are designed with amazing build quality and you are guaranteed that they will benefit from their exceptional features. The main difference is that the Vortex Viper is designed with a 6 MOA dot while the Fast fire model makes use of a 3 MOA dot. Both MOA dots are guaranteed to provide you with a lot of precision and they can work well in all conditions.

Verdict: Which is better – The 3 MOA or 6 MOA?

The 6 MOA Vortex Viper Red Dot is more ideal than the 3 MOA Fastfire model. The sight’s intensity settings and size play a major role here. Decreasing the size of the intensity can allow the red dot to appear smaller and an optimum level of precision is provided. The much smaller 3 MOA red dot cannot cover the whole target when compared to the larger 6 MOA red dot. When working with the smaller 3 MOA red dot users may only get a split second to achieve a shot, however, a 6 MOA works well providing users with an optimal view and level of accuracy for their shot.


  1. Do Red dot sights have any kind of parallax?

It is not possible to achieve an accurate parallel reticle image, therefore most of the red dot optics in the market gauge the image of the reticle forward. The distance that is estimated is the distance where the sight is parallax free. The direction in which you move your head does not matter as your reticle will continue to maintain a steady position on your target.

  1. Are red dot sights accurate?

With a red dot sight, you can be sure that your head position will not manipulate the precision of the red dot sight. The parallax, however, will come up as soon as the shooter begins to approach the target.


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