Rifle Barrel Steel: Why It Matters

If you’ve ever read a product specs description of a rifle or pistol you’ve likely seen a line about what that barrel is made out of.

But how many of us actually understood that part or even paid any attention to it?

I’ll bet it’s a lot less people than bought the gun.

I like my barrels like I like my music, made from heavy metals. But what metals are the best? What ones matter? Let’s dig in and find out!

Does Your Barrel Material Really Matter?

I grew up in the Boy Scouts and got my Eagle Scout at a young age. Being the outdoors type, I’ve always had a deep appreciation for a good knife. But honestly, the knife community can be overbearingly annoying because of a constant snobbery about the exact metal composition used in their knives.

If you’ve ever felt that way too, you might shudder at the thought of having to consider what your barrel is made of. I get that.

Thankfully, while there are dozens of alloys to make a knife out of -- barrels are much more limited and more straightforward with more quantifiable benefits.

The huge bottom line is that yes it matters, but this is an advanced topic for advanced users.

The general user, the casual plinker, and the few times a year competition shooter are very unlikely to see a major difference between one barrel material and another.

My goal with this article is to teach you some good to know facts about metallurgy and the types of metal used for barrels and to teach you specifically why 416R stainless steel is a great metal.

Spoiler alert, 416R is what Bear Creek Arensel uses for their stainless steel barrels.

[Shop accurate AR-15 barrels and AR-10 barrels from Bear Creek Arsenal.]

What Is Steel, Carbon Steel, and Stainless Steel?

The two huge general categories of metal that can be used for barrels are stainless steel and carbon steel.

Steel is simply iron and carbon. Both carbon steel and stainless steel start with the same basic ingredient -- steel (iron and carbon).

The difference is that carbon steel has up to 10.5% other stuff (nickel, copper, zinc, just about anything depending on the application) while stainless steel must contain at least 10.5% chromium in addition to the other stuff.

Chromium reacts with air to form a thin passive layer of chromium oxide, this helps seal the iron in the steel from the air and helps prevent rust.

What exactly all of these metals do and how much of them are used in different steels is a really in the weeds question that honestly doesn’t make any difference to you. The hard facts of this are that different steels have different stuff in them, but they are also made in different ways.

How steel is made and what it contains gives it different properties.

Benefits of Stainless Steel

First of all, stainless steel in the 400 series (the family of stainless steel used in barrels) isn’t truly “stainless”. While 400 series stainless steel is corrosion-resistant, it is not corrosion-proof. 400 series stainless steel can still rust -- so don’t just put them away wet and ignore them for weeks. It’s just harder for it to rust than carbon steel.

Okay, that said, the corrosion resistance of stainless steel is a huge benefit and shouldn’t be ignored at all.

On top of that, the major gain you get from stainless steel in a rifle barrel is that stainless steel is more durable.

Fundamentally, stainless steel is stronger and more resistant to heat than carbon steel is. This gives you a barrel that will last longer and shoot better.

How much longer depends on how you treat your barrel, so I can’t say that a carbon steel barrel will last X rounds and a stainless steel barrel will last Y rounds.

What I can tell you is that if your carbon steel barrel would start to wear out at X rounds, a stainless steel barrel used the same way will likely last at least 20% longer.

Carbon Vs. Stainless Steel Barrel Accuracy

There is a pervasive myth floating around that stainless steel barrels are more accurate. They aren’t. Kind of.

This comes directly from some of the best barrel makers in the world -- the host material for a barrel is more or less irrelevant to the accuracy potential of the barrel.

How the barrel is made is far, far, far more important.

That said, stainless steel lasts longer and costs more. If a great barrel maker is going to make a great barrel, they are likely going to use a material that allows their barrel to last as long as possible and helps justify the cost of making it.

Thus, almost all great barrels you see on the market are made from stainless steel of some flavor.

Why Carbon Steel?

So after reading all of that you might be wondering why carbon steel is even used.

Easy, money. Dollars. Greenbacks. Bennies. You get the idea.

Carbon steel is cheaper to buy and easier to machine.

Easier to machine is a bigger deal than most people understand. Easier means the manufacturer can make them faster, since time is money this is a big deal. It also means that carbon steel wears down tools less, this means less breakage and fewer problems that suddenly occur.

Carbon steel is also not as far behind stainless steel as you might think, depending on what you do to it afterward.

While stainless steel has some natural corrosion resistance, carbon steel is easy to coat and seal against corrosion. An untreated carbon steel barrel will rust very quickly, but pakerized and lined with chrome-moly and a carbon steel barrel becomes highly corrosion resistant with outstanding durability.

416R Stainless Steel

Normal 416 steel (note this is 416, NOT 416R) is a standardized stainless steel that has the highest machinability of any stainless steel, meaning it’s easier for manufacturers to work with.

It has good corrosion resistance, it’s easy to work with, and is very heat resistant -- rated for continuance use up to 1,250F degrees (that’s really hot, way hotter than your barrel is going to get while shooting).

But… to make 416 steel sulfur is added to the alloy. While this improves a lot of properties, it kind of nukes the ability of the steel to perform at very cold temperatures, namely it becomes very brittle at 0F or lower temps. For me in California, that’s a non-issue, but since some people work, live, and enjoy places that cold -- it’s an issue.

416R stainless steel is proprietary steel made by Crucible. You can’t get this steel from anyone else, they are the people that invented it and the people that produce it.

They designed it specifically for precision rifle barrels and it’s an awesome steel that is used by basically everyone that wants to make the best stainless steel rifle barrels.

I don’t know what magic herbs and spices Crucible uses in their 416R stainless steel, but their steel retains the machinability and corrosion resistance of 416 steel but is rated to work in temps as low as -40F. Now THAT is cold.

Wrapping Up

Most people don’t know or care what their barrel is made of and that’s okay. What is important is that Bear Creek Arsenal knows and cares about it.

Because of that, they choose to use the best 416R stainless steel.

Even if you’ve never thought about what your barrel is made of until today, it’s good to know that the people behind your barrel put in the effort.

[We'd like to extend a huge thanks to David Lane for his hard work on this article! Make sure to check out our AR-15 Barrels, AR-10 barrels, and AR-9 barrels with over 14 calibers to choose from, all cut by us from the finest steel with high accuracy guaranteed. Take a look at the process below.]