Airsoft Red Dot Sights
Back-Up Iron Sights (BUIS) is a bit of a misnomer nowadays, however, the name is ubiquitous. The sights can be made out of Iron (Steel), Aluminum, or even Polymer. This is why the name is a bit of a misnomer and can cause a little bit of confusion when people are trying to find appropriate back-up sights for their airsoft guns. There are pros and cons to each material, much like all things in life. The most common material these sights are made of is aluminum. This will usually give the best balance between strength and durability. Considering they are primarily used in a back-up capacity, they can even be made of polymer to save weight for the majority of the time that they're living dormant on your Airsoft Gun while you use your primary sighting system.
Some people share the school of thought that with modern optics and how reliable they've become that Back-Up Iron Sights (BUIS) are obsolete so they opt to not use them on their rifles. We believe it is kind of like insurance, it's something you may not use all the time but when you need it, you will be very happy that you did. Also if you have the real estate to mount the BUIS, it is probably a good idea to mount a front and rear set of sights. Airsoft BBs can shoot out or break your Magnified Optic or Electronic Reflex Sights lens. In this scenario, it would be advantageous to be able to immediately deploy your BACK-UP sights and keep playing. This would allow you to still be combat effective and continue engaging targets vs. packing up and going home for the day. Depending on your optics and its mounted height, it's possible to achieve an absolute co-witness or lower 1/3 co-witness sight picture with your Electronic Reflex Sight. This allows you to see and aim through your primary optic with the back-up sights.
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Q & A:
Q: Is it better to have Backup iron sights that lock into position or just require force to overcome?
A: That is a matter of personal preference. Sights that lock in the up position are arguably better if that is going to be your primary sighting system. If they are being used truly as a back-up sighting system, then it is less important. Sights that do not lock are quicker to deploy and stow.
Q: Where should I mount my back-up sights on my Airsoft gun?
A: There is no right answer, there are some preferred locations when mounting BUIS, however, each person's gun is set up slightly different, and depending on the accessories that are mounted to that rifle you may need to move the sights into an optimal position for compatibility but that may also be a suboptimal position for the maximum sight radius. Given their back-up nature, it's generally okay to sacrifice sight radius.
Q: Is there one brand or style that is better than another when shopping for BUIS?
A: No, I would go with what fits your priorities the best or checks the most boxes. Some people like to build clone guns (replica's of specific real guns used by various military forces/units). Other people just want something that works, in that case, your options are limitless, pick whichever sights fit your budget and preferences.
