AR 15 barrels

**rich** · August 29th, 2007, 03:03 PM

I hate to ask more foolish questions but I was looking at AR barrels and wanted to know what the difference between chrome moly and chrome lined is and if either one was better than the other?

**Pa. Patriot** · August 29th, 2007, 03:21 PM

In simplest terms:
Chrome Moly is a type steel and Chrome lined is hard-chrome lining of the rifleing and/or chamber.

Much debate (search) but essentially the crome lined is generally more reliable and longer lasting and the non-chrome lined can be more accurate.

**Xringshooter** · August 29th, 2007, 03:28 PM

You are going to get a lot of answers to this question, both pro and con for both types. Here is my opinion. If you clean your guns after every shooting session then either will work fine. If you're prone to clean just every so often then I'd go with the chrome lined as it is a little more corrosion resistant (but not like SS). IMO the chrome lined is easier to clean, the crud doesn't seem to build up near as much as a non chromed barrel. Now be aware, if you look down what is called a chrome lined barrel it WILL NOT look like a chromed handgun. The chroming of the barrel and receiver is more on the molecular level whereas a chrome plated firearm is just that, a plating put on the outside of the firearm.

Some very well made firearms are made with the chrome-moly barrels with the chrome lined barrels as options. The chromed lined came about as a result of the abuse that M-16's got in SEA and the lack of good cleaning procedures in the field (you didn't always have the time to properly clean your weapon after a firefight and before the monsoon rains hit).

One other point, think about your hunting rifle, your dads hunting rifle, your granddads hunting rifle. How many of these had chrome lined barrels? How many are still in great shape and still can shoot better than you can aim?

IMO, if you are going to use it hard and maybe not have a chance to clean after use, then you might be better off with the chrome lined.

**Lycanthrope** · August 29th, 2007, 11:16 PM

They have it covered.

Lycannooneneedsmeanymorethrope

**LastManOut** · August 30th, 2007, 08:32 AM

Question along the same lines, didn't the older AR's have a different twist, then manufacturers reduced the twist for better accuracy?
There may be some of the "twistier" surplus barrels still on the market, and that may make a difference in choosing a barrel.

**VeryPrivate** · August 30th, 2007, 08:54 AM

The original twist rate was1 in 14". This was increased to 1 in 12". These were used for the M193 55gr FMJ round. With the A2, the twist was increased to 1 in 7" for the M855 62gr round (historical note: it was the M856 tracer round that dictated the twist rate). Today 1 in 9" is most common and works with both 55 and 62 gr bullets. Heavier and longer match grade bullets (e.g. 69gr and 77gr) need the faster twists of 1 in 8" or 1 in 7" and these rates are available.