First AR-15 Buying Guide: What to Look For and How to Buy

The Short Answer

For most people, a good first AR-15 looks like this:

• A complete rifle or pistol from a maker that stands behind it, not a box of parts.
• Chambered in 5.56 NATO (or .223 Wylde), so it fires both 5.56 and .223 Remington ammo.
• A mid-length gas system and a 1:7 or 1:8 twist barrel.
• An M-LOK handguard with room for a light and a sling later.
• A red dot or other optic, or at least iron sights. Many rifles ship with neither.
• A real warranty, and a seller who ships to an FFL dealer near you.

The rest of this guide explains each point in plain English, so you know what you’re paying for.

Caliber: 5.56 NATO, .223 Wylde or .22 LR

Start with 5.56 NATO. It’s the most common AR-15 cartridge, ammo is easy to find, and the recoil is mild.

5.56 NATO vs. .223 Remington vs. .223 Wylde

These names describe the chamber, the part of the barrel that holds the cartridge. They aren’t the same:

• 5.56 NATO chamber: fires both 5.56 NATO and .223 Remington ammo. The safe, flexible choice.
• .223 Remington chamber: made for .223 Remington ammo only. Don’t fire 5.56 NATO in it, because 5.56 runs at higher pressure.
• .223 Wylde chamber: a hybrid that fires both, with dimensions aimed at accuracy. Many precision-minded barrels use it.

Either 5.56 NATO or .223 Wylde is a good pick. Check what’s marked on your barrel and buy ammo that matches. One Horse 5.56 rifles and pistols are sold as 5.56/.223, with 5.56 NATO listed on the spec sheet.

.22 LR: the low-cost trainer

.22 LR ammo costs far less than 5.56 and has almost no recoil. A .22 LR AR lets you practice the same basic controls (safety, magazine release, charging handle) for a lot less money, and it’s a great way to bring a new shooter along. A dedicated .22 LR rifle has a barrel, chamber and bolt made for the cartridge, unlike a conversion kit.

Other calibers, like .300 Blackout and 6mm ARC, are great for specific jobs, and we build rifles in both. For a first AR-15, start with 5.56.

Barrel and Twist Rate, in Plain Words

Barrel. Look for good barrel steel with a protective treatment, such as nitride or a chrome lining, to resist wear and corrosion. Profile is the barrel’s shape and thickness: lighter profiles are easier to carry, heavier ones (like HBAR) add weight but handle heat better.

Twist rate. Grooves inside the barrel (the rifling) spin the bullet so it flies straight. Twist rate tells you how much. A 1:8 twist means one full turn every 8 inches. The smaller the second number, the more spin.

• 1:8 is the most versatile, from common 55-grain range ammo to heavier bullets.
• 1:7 is the military standard and favors heavier, longer bullets.
• 1:9 does well with lighter bullets but can struggle with the heaviest ones.

For a first AR-15, 1:7 or 1:8 is a safe choice. Our 16-inch 5.56 rifles use a 1:8 twist and our 10.5-inch Express pistols use 1:7. The Express .22 uses a 1:12 twist made for .22 LR.

Optics or Iron Sights?

What Comes in the Box (and What Doesn’t)

Read the listing, because every maker is different. A complete AR-15 usually comes with:

• The rifle
• At least one magazine
• An owner’s manual

What usually isn’t included:

• Sights or an optic
• Extra magazines
• Ammo
• A sling and a weapon light
• Eye and ear protection
• A cleaning kit
• A case, and a safe or lock for storage

Each One Horse product page lists the magazine that comes with the firearm and shows add-ons, like Vortex optics.

Warranty

A warranty shows how much a maker trusts its own work. Before you buy, ask:

• How long does it last?
• What does it cover, and what doesn’t it cover?
• How do you file a claim?

One Horse rifles carry a Limited Lifetime warranty against manufacturing defects. If a One Horse product fails from a defect in materials or workmanship, we repair or replace it. Normal wear, misuse and modifications aren’t covered. Details are on our Warranty & RMA page.

Age Rules and Local Laws

Federal law sets the floor. States and cities can add more.

• Rifles: under federal law, you must be at least 18 to buy a rifle from a licensed dealer. Some states and cities require you to be 21.
• AR pistols: these count as handguns, and buyers must be 21 or older to buy one. State and local rules can add more, so check before you order.
• The rifle itself: some states restrict AR-15s, magazines, certain features, or certain triggers and selectors. Others require a permit or a waiting period.
• The seller: sellers can set their own rules. One Horse Express rifles are sold to buyers 18 and older, or 21 where state or local law requires it. Express pistols are sold to buyers 21 and older.

This guide is general information, not legal advice. Laws vary and change. Check your federal, state and local laws, and ask your FFL dealer, before you buy.

First AR-15 FAQ