Aligning front/rear sights
Sight alignment is the process of properly lining up the eye with the rear and front sights on open or aperture sights.:)
How do you sight a power line 880 bb gun?
AIM B Style Red Dot Gun Sight-wrong your barrel
The front sight is called "the front sight."
Yes, a front and a rear sight.
One can learn how to sight a gun without firing it by practicing with an unloaded gun, using a laser bore sight tool, or seeking guidance from a professional instructor.
it might be referring to the type of sight used on the gun (holographic sight), not the gun its self.
There is no restriction on age for a sight in the USA.
It is the image that a shooter sees when looking through the sights of a firearm at a target, and shows the alignment of rear sight, front sight and target.
the process of lining up a firearm's rear and front sights
Telescope
One can purchase front sight for a gun in websites that sell gun apparel, accessories and equipment such as FrontSight, Guns4Survival, NewEnglandCustomGun and other outlet gun stores all over the world.