First let s have a discussion about the chemical elements of each material and how their properties effect barrel life accuracy and cost.
Chrome moly vs stainless steel ar 15.
Steel is alloyed with other metals like nickel and chrome as well as other non metals such as carbon sulfur and silicon.
Without the chrome they are finished a little more rough in.
Stainless steel ar 15 barrels.
Cm and stainless barrels machined bare have about the same level of accuracy.
When we start talking about stainless steel barrels everyone assumes we re talking about precision rifles and match grade barrels.
Chromium molybdenum specifically means a family of steel alloys that when used for hand tools have a moderate amount of carbon often around 0 4 to 0 5 around 1 chromium around 0 15 to 0 20 molybdenum and a range of other alloying elements.
This is where the real differences between chrome moly cm and stainless barrels become apparent.
Some other manufacturers prefer to chrome line the inside of their ar barrels and some do not.
Chrome moly means chromium molybdenum alloy steel the usual material for gun barrels and other parts excepting things like aluminum ar recievers of course chrome lined means that the bore and chamber of a barrel probably made out of chrome moly alloy to start with has been plated with metallic chromium.
Multiple steel types are used in the manufacture of the nbsp ar 15 barrel.
Regular 4140 moly is just a regular barrel steel it will last a long long time with the most often used twist rate on one turn in 9 inches.
So which steel is the best ar 15 barrel material then.
The name given by the society of automotive engineers sae usually follows the pattern 4xxx.
