Optics in firearms can offer you different benefits such as extended range, low-light visibility and also on the ease of target acquisition. Even the military today now switched to optics to use for combat situations.
It is however essential that you remember that such high tech replacements for dependable old iron sights could be disabled in a certain way. If there’s no proper backup, damaged optics could make the weapon useless for an accurate shooting.
A BUIS or Back Up iron sights can actually give you critical redundancy in setting up your AR. It could add weight, but could give you the ability in getting targets even after the primary sight goes down. What you will learn below are some things to consider in the selection for a backup iron sight.
Iron sights are available in various configurations based with the height of the sights. The basic concept to this is that you need the front and also the rear sight to have the same height when you wish to hit the target.
This comes to play with where you are mounting your flashlight mount. Most backup iron sights are available in 2 options which are the gas block height and same-plane height.
In the gas block BUIS configuration, its front sight post is 1/4 ” higher compared to the rear sight aperture in order to make up for the case where the front sight is mounted to about 1/4 ” lower than the upper receiver to where the rear sight is mounted. You should bear in mind that the gas block sights are only for mounting on gas blocks to which are usually lower than the upper receiver. Some of the gas blocks have the same height with that of the receiver to where you want the same-plane sight is.
The same-plane sights are made so that the front sight post is on the same height as the rear aperture when the sights are being put on a flat surface. This actually means that for these sights, the front sight should be mounted somewhere with the same height as its upper receiver. In most cases, people will mount the front sight on a free float handguard with a rail present on top.
The overall AR-15 setup will help determine if you need the fixed or folding BUIS. The fixed iron sights has the advantage to where it comes with no moving parts where it makes it nearly indestructible. Also, it’s always ready and there’s no need for you to mess with it.
When you are however not using them as the main targeting system, the fixed sights would be the best choice, but for backup purposes, it’s the folding type that’s best. Be sure to visit this website at https://en.wikipedia.org/wiki/Gun for more facts about guns.