The .223 Remington and 5.56 NATO cartridges are based on the .222 Remington, an old varmint hunting round designed to be fired from a bolt-action rifle. That rifle was the Remington Model 721, to be exact, which had a 24″ barrel. In other words, the 5.56 and .223 cartridges we all chamber in our AR-15s…
The importance of the AR-15’s gas port is often overlooked. When there’s talk about gas systems and tuning a rifle, the conversation usually focuses on gas blocks, buffers, and gas tubes. There’s little mention of gas port size. Maybe you’re building an AR-15 from an 80% lower, and need to verify you’ve got the right…
This guide covers all the important aspects of the AR-15 barrel: Rifling, forging, and barrel steel, treatments and coatings, and the best barrel lengths and twist rates for the most popular cartridges. What is a “Twist Rate,” Exactly? A barrel’s twist rate describes how tightly a gun barrel’s rifling twists. The rifling rotates the bullet…
Whether you build or buy a rifle, picking out a barrel is arguably the most important thing you’ll do. After all, the barrel determines how your rifle performs; everything else comes second. In addition to choosing between carbon and stainless steel, and your barrel’s type of rifling, you’ve got to pick what finish — if…
Every shooter wants the most accurate and reliable barrel. If you’re building a new AR-15 or just buying a rifle off the shelf, you’re probably deciding between different types of rifling: Cold-hammer forged (CHF), cut rifling, and button rifling. Which one’s the best? Is one the best? Each type of rifling offers advantages (and suffers…
We’ve explained parts compatibility in our 300 Blackout AR-15 build guide. In that guide, we explained how, technically, the .300 AAC Blackout cartridge can be stacked in standard 5.56 NATO magazines — but there’s a critical caveat that needs to be covered. The short n’ sweet summary is this: Although 300 Blackout rounds can fit…
Stainless barrels have gained popularity rapidly. In the past few years, they’ve taken the AR-15 market by storm. Nowadays, you’ll find plenty of accuracy-focused upper receivers and prebuilt rifles configured with 416R stainless barrels. But 4150 barrels — commonly called “carbon steel” barrels — remain arguably the most popular. So, which is better: 416R stainless,…
The AR-15’s capable of incredible accuracy, and it’s one of the most reliable firearms ever designed. But its mass production, myriad manufacturers, those makers’ tendencies to focus on affordability, and the classic effect of “tolerance stacking” (small imperfections in components adding up to noticeable issues) mean that your fresh AR build — or that rifle…
Does your AR feel a bit too punchy in the shoulder? Are you pulling your bolt after a modest range day, only to find it’s caked in carbon fouling? Getting a little too much heat in your face when you run a suppressor? These are all symptoms of the likelihood that your AR-15’s over-gassed. There…
Gun barrels are made from just two types of steel: Stainless, and carbon. When it comes to putting rounds on a target, both types of steel provide different benefits and drawbacks. So, which barrel steel’s better? Is one even truly “better,” overall? Let’s cover it — but first, we need to learn what both steels…
