Chrome moly vs chrome vanadium is a wash.
4140 chrome moly steel vs 416 stainless.
Some manufacturers prefer to use 4140 or 4150 steel while others prefer to use 416 ss or 416r steel for its properties.
So let s now look at its strengths.
Most often this would be either a chrome moly steel such as 4140 or a stainless steel such as type 416.
Some other manufacturers prefer to chrome line the inside of their ar barrels and some do not.
Aisi 4140 chrome molybdenum steel can be oil hardened to a relatively high level of hardness.
I have always heard that stainless shoots better but would not hold up as good under repeated rapid fire not talking about full auto and was easier ruined than a steel barrel.
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.
Other considerations are secondary such as its ability to be blued or resistance to corrosion.
So which steel is the best ar 15 barrel material then.
416 r is stainless in name only as it is still susceptible to corrosion but at a reduced pace.
The important characteristics of the steel are its machinability longevity and strength.
I wanted your input on how 416r would hold up vs something like 4150 cmv steel barrel.
The barrel maker must choose the type of steel the barrels are made from.
The chromium content provides good hardness penetration and the molybdenum content ensures uniform hardness and high strength.
Most often this would be either a chrome moly steel such as 4140 or a stainless steel such as type 416.
It is a high carbon content steel which makes it resilient to high heat scenarios and with its abrasion resistance the barrels wear slower over time.
Aisi 4140 is a chromium molybdenum alloy steel.
The common grades of alloy steel have a skooch less than 1 chrome which is way more than is needed to ensure something as skinny as a rifle barrel achieves hardness to the core.
The primary purpose of the chrome is to increase depth of heat treatment for a given severity of quench.
