With all the shooting accessories available for your AR-15, it can be hard to figure out what to purchase first.
Establishing a solid optics platform tailored to suit your needs is a great starting point – it will help you decide what stock, grip, sling, forend and other accessories to get. Also, your average shooting distance will be the largest factor in determining what type of optics / scopes will go on your rifle.
What Type of Rifle Optics Do You Need?
Close Range Rifle Optics (0-100 yds.)
Options for close-range shooting include iron, red-dot, reflex and holographic sights. These optics are designed for fast target acquisition and both-eyes-open shooting, and can be paired with a laser and/or light. Low-power scopes are also popular, but target acquisition can be slower at extremely short distances and in low light. With standard-height sights and most common cartridges, a 100-yd. zero usually results in a point-of-aim/point-of-impact difference of less than 3" between 5 and 200 yds. – eliminating hold over/hold under for most practical purposes.
Moderate Range Rifle Optics (50-200 yds.)
Low-power magnified optics are the frontrunner in this category. You may choose to use a variable-power scope (popular models are 1-4X and 1-6X), a fixed-power scope (3X or 4X are good choices), a prism sight or add a magnifier to an electronic sight. Range time will be the ultimate decider, but setting your zero at 200 yds. should provide a point-blank range of nearly 250 yds. Moderate-range scopes can be paired with a small reflex sight mounted at a 45° offset, allowing for both precise, magnified shooting and quick, close-range shots.
Long Range Rifle Optics (200+ yds.)
A variable-power scope with a top end of at least 9X magnification is your best bet for long-range shooting. Many scopes have caliber-specific hold-over marks on their reticles, and some even have custom turrets matched to your ballistic and environmental conditions. While your zero will be determined by your shooting situation, 200 yds. is a popular distance.