When I retired it was the optic systems you had to qualify on such as your ACOG or EoTec.
As the years have passed the evolution of the metallic sights has improved over the years and continues to improve with technology. Sights are nothing new as they have been around for over 500 years. Sights started out as wheel-locks, flint-locks, and match-locks and have evolved into metallic or iron sights. The simplest of the metallic sights are the bead sights. Beads sights can either be round or square and made of brass, German silver, gold and silver beads. Bead sights are usually used on hunting rifles. Some other types of metallic sights are peep sights, open sights, and target sights. The selection of the sight depends on the need of the owner; such as someone who shoots targets will need a target sight not necessarily a bead or peep sight. Once the owner of the firearm selects the proper sight they will need to sight or zero it in to them. Firearms coming from the factory will have been sighted in to the person at the factory, which may be off from the new owner. Each sight will have its own method to