Discussion in 'On Topic' started by GlobeGuy, Jan 16, 2008.
What are the differences?
Chrome-Moly is a type of steel commonly used in rifle barrels, chrome-moly is a modified 4140 type steel. Chrome Lining is a thin layer of chrome inside a barrel to help prevent corrosion and make cleaning easier.
Thank you. Which is better?
Found the answer, copy pasted below for those who are also interested.
Q: What is the difference between Chrome/Moly and Chrome Lined? How does Stainless fit in?
A: All manufactures use Chrome/Moly steel to make barrels - its a type of steel that has some chrome in it to help with wear and corrosion resistance IT IS NOT the same as 'Chrome Lined'. There are two types of Chrome/Moly that are used to make AR-15 barrels. The most common (an most inexpensive) is 4140, its a decent steel that is used on many firarms. The other (more expensive) type is 4150, its got more chrome in it and is more durable and corrsion resistant; only Colt, Bushmaster, and FN use 4150 steel for their barrels. A 4140 chrome/moly barrel is the least expensive barrel you can purchase - yet they can be quite accurate.
Chrome Lining is a process where chrome is 'welded' to the steel of the barrel. This produces a coating that is twice as hard as the steel. It prevents corrosion, makes cleaning much easier, and extends the barrels life. There is also a slight drop in accuracy (compared to an identical quality non-lined barrel), about 0.5 MOA worth from what I've seen - something 99% of shooters won't notice. Chrome lined chambers are a reliability enhancer. Only chrome/moly barrels can be chrome lined. Bushmaster and Armalite chrome line their barrels, Colt chrome lines their chambers (and the bores on their military profile barrels), and RRA has produced limited runs of chrome lined M4 barrels. Chrome lined barrels have the longest life expectancy.
Stainless barrels are used on match rifles. The Stainless steel is easier to rifle consistantly, and consistancy is the key to an accurate barrel. Once broken in stainless barrels are almost as easy to clean as chrome lined. Stainless barrels are also very corrosion resistant. Some companies (like Olympic Arms) have a process that blackens the stainless, others (like DPMS) leave the barrels 'in the white' (silver color). Generally the most accurate rifle have stainless steel barrels.