Chrome Moly or Stainless Steel

First, let’s have a discussion about the chemical elements of each material and how their properties effect barrel life, accuracy and cost.

4150 Chrome Moly:

Steel is alloyed with other metals like Nickel and Chrome as well as other non-metals such as Carbon, Sulfur and Silicon. Each element changes the properties of the mix in order to gain desired characteristic like machinability, corrosion resistance or strength.

A major factor in metal hardness is its percentage by weight of Carbon. Metal has a crystalline structure and the small Carbon atoms find their way in-between the iron atoms when alloys are heated, strengthening the crystalline structure. By quickly cooling the heated metal the Carbon atoms are frozen in place resulting in a much stronger and harder metal.

As the name implies Chrome Moly steel has chrome as part of its alloy; about 1%. This is not enough to inhibit rust but it does increase the tensile strength combined with Carbon to around 100,000 psi and increases the yield strength in the range of 75,000 psi after proper heat treating.

416R Stainless Steel:

Stainless Steel is designed for corrosion resistance. With a much higher content of Chrome than regular steels. This Chromium forms a passive film of Chromium Oxide about the outer surface which prevents corrosion by blocking oxygen diffusion at the surface and preventing its spread into the internal structure of the metal.

416 Stainless also has the ability to be heat treated due to its 1.5% by weight composition of Carbon, even more than Chrome Moly steel but its 13% Chrome composition is plenty high enough to deter any type of corrosion.

So, let’s now look at its strengths. Tensile strength of 416 Stainless falls into the 75,000 psi range and its yield a low 40,000 psi.

Stainless Steel with its additives gains a characteristic machinability factor that greatly improves surface finish. This will be the foundation of your barrel decision after reading this entire article.

So, how do I choose?

When deciding on a Ballistic Advantage barrel corrosion should not be a factor, even if you live in a humid or salty environment due to the fact that all of our Chrome Moly Steel rifle barrels are coated with high quality QPQ Melonite.

Many tests have been conducted about the longevity of Alloy steel barrels verses Stainless Steel rifle barrels. Chrome Moly barrels always outlast Stainless Steel barrels but only by a narrow margin.

Why in the world would I choose an expensive Stainless Steel barrel over a Steel barrel after learning all this information about these two steels? It all depends on what type of shooting you are doing.

The machinability of Stainless Steel is much greater than that of Chrome Moly Steel and due to this fact the surface finishes will be much smoother and this is most important in the throat of the bore due to the fact that this is where fouling begins and the spread of impurities throughout the barrel. So, Stainless Steel fouls less and is easier to clean. This is why I should spend the extra money?

No, due to less fouling and better finishes the Stainless barrel is up to 30% more accurate than its Chrome Moly counterpart as long as you are not continually firing the firearm and heating up the barrel. Due to the low yield strength as stated above Stainless Steel has a much smaller effective temperature range of use. Whether it be extreme cold or high heat.

Well, guess where that leaves us. A few accurate shots very precisely placed at a reasonably controlled temperature? Competitive shooting. Stainless Steel is the hands down winner for accuracy and repeatability at a competitive shoot.

Meanwhile back at Ballistic Advantage we have increased the accuracy of Chrome Moly barrels by leaps and bounds through the latest manufacturing techniques and optimum process control. A Chrome Moly barrel with an effective corrosion resistant coating is your best choice barrel unless you are a competitive shooter.

Shop Ballistic Advantage barrels here: AR Barrels

by: Gregg FIkes