what is a chromoly AR-15? they are cheaper?? why?

Chrome-moly is short for Chromium and Molybdenum, two chemical elements added to carbon steel to give it better physical properties.

When you see "chrome-moly" listed in a barrel advertisement, it simply means the barrel is a high grade carbon steel, but there is nothing particularly special about it, and it is by no means chrome lined.  That's why they're cheaper.

Quoted: Chrome-moly is short for Chromium and Molybdenum, two chemical elements added to carbon steel to give it better physical properties. When you see "chrome-moly" listed in a barrel advertisement, it simply means the barrel is a high grade carbon steel, but there is nothing particularly special about it, and it is by no means chrome lined.  That's why they're cheaper.

By and large chome-moly barrels ARE chrome lined.  USGI mil-spec M16 and M4 barrels are chrome-moly steels with chrome lining.  Chrome-moly does not necessarily mean chrome lined, but they usually are.

Quoted: Quoted: Chrome-moly is short for Chromium and Molybdenum, two chemical elements added to carbon steel to give it better physical properties. When you see "chrome-moly" listed in a barrel advertisement, it simply means the barrel is a high grade carbon steel, but there is nothing particularly special about it, and it is by no means chrome lined.  That's why they're cheaper. By and large chome-moly barrels ARE chrome lined.  USGI mil-spec M16 and M4 barrels are chrome-moly steels with chrome lining.  Chrome-moly does not necessarily mean chrome lined, but they usually are.

Most barrels advertised as Chrome Moly are not chrome lined.  RRA, M&A, et al...

TS

Chrome-moly is the type of steel the barrel is made of...

Here's a brief description of the different type barrels that are available...


Stainless Steel:
Stainless steel is much more corrosion and rust resistant than normal chrome-moly but doesn't compare to chrome lining... They resist fouling and clean up easier than chrome-moly barrels and typically last as long as chrome-moly barrels do... They have the ability to be highly accurate when broken in properly too... You can expect thousands of rounds with proper maintenance and no abuse...

Chrome-Moly
Chrome-moly barrels have the ability to be highly accurate when broken in properly and are the least expensive of barrel choices... Unlined chrome-moly barrels normally have the shortest life of any material because they experience erosion from bullet friction at a faster rate compared to chrome lined barrels... If used as semi-auto only, this life can still be thousands and thousands of rounds... Plain chrome-moly isn't resistant to corrosion or fouling and is the most difficult to clean... With all of this said, a quality unlined chrome-moly barrel will more than suffice for the average AR15 owner...

Chrome-Moly, Chrome Lined:
Chrome Lined is basically a chrome-moly barrel where the barrel and chamber are internally lined with a thin layer of chrome through an electro-plating process... Chrome lining offers resistance to rust, corrosion, fouling and is easier to clean... Barrel life is also extended when chrome lined...


Lining a chrome-moly barrel with chrome also has the possibility of reducing accuracy... Therefore, a chrome lined barrels is often used more as a work/CQB/SHTF barrel, not as a match/target/competition barrel... Although I have seen some truly excellent accuracy from various chrome lined barrels... MOA can easily be obtained from a quality barrel that is properly chrome line...