Guns: AR sights, past and present
(Note - for more info about rifle sights and rifles in general, check out THR's comprehensive post listing)
The AR family of rifles is firmly entrenched in today's shooting community - they're fun to shoot, fun to build, and fun to talk about. But a rifle is nothing without sights, so I thought it'd be interesting to take a look at how AR sights have evolved over the years.
I suppose the original AR-15 sights were similar to Vietnam-era M16s - that is, the "A1 sight." The rear sight is integrated into the carry handle of the rifle, and it has no adjustments for elevation (up-and-down), only windage (side-to-side). Still, the simplified design means fewer parts and less stuff to break; A1 sights are still popular for people who want something simple and rugged. The sight's main aperture is also noticeably smaller than later versions - a throwback to a different kind of rifle sight for a different kind of fighting.
Most modern stock ARs come with either a regular carry handle or a detachable one, and each features an "A2 sight." The rear sight of the A2 style has a second dial for adjusting windage, and the rear aperture has both a very large ghost ring (excellent for short-range shots) and a small peephole (for longer range work and formal target shooting).
Much more popular nowadays is to mount some kind of optic onto an AR carbine. The most famous (and one of the most expensive) of these is the compact telescopic ACOG line of scopes manufactured by Trijicon. These are lit either by tritium at night or a fiber-optic in the day. I'm most familiar with the donut-style reticle shown above - nicknamed the "donut of death" by its owners.
I've also used EOTechs and Aimpoint red dot scopes with much success. These sights are FAST when you're shooting at targets less than 50 yards away - almost like playing a video game. At longer ranges, though, they're not as precise. And in the fairly unlikely event the batteries give out, you'll be relegated to either flip-up back-up irons or using the scope itself as a crude sight.