I'm getting ready to build a flat top upper with a free float barrel. Does anyone have thoughts on barrels to stay away from? Recommendations? Any help or comments would really be appreciated.

What do you want to build?  A carbine?  Rifle?  Mid-length?  

I would suggest sticking with the big names; LMT, Bushmaster, RRA, Armalite & CMMG.  All offer the best barrels with chrome lining in a variety of configurations.

I'm looking to build a 20" rifle. I ask this question because I'm going to Knob Creek this weekend and should be able scab together just about all the parts I need. So are the general thoughts that a chrome moly, chrome lined barrel is better than SS?

Bushmaster chrome lined A2 (gov't profile) would be my first choice in a 20".

Quoted: Bushmaster chrome lined A2 (gov't profile) would be my first choice in a 20".

+1

Why the gov't profile and not the heavy barrel?

Quoted: Bushmaster chrome lined A2 (gov't profile) would be my first choice in a 20".

Got to agree, +1.

Quoted: Why the gov't profile and not the heavy barrel?

Because heavy barrels are HEAVIER...


Bushmaster chrome lined A2 (gov't profile) would be my first choice in a 20".
+3

Quoted: .. So are the general thoughts that a chrome moly, chrome lined barrel is better than SS?

Chromoly steel and chrome lined are not the same. Chromoly steel is just a cheap steel they use for barrels. Chrome lining is a hard coating they put inside the bore to prolong barrel life.

IVe heard people say SS barrels are more accurate. They also require more cleaning from what ive heard.

I'm considering a heavier barrel for better accuracy (if that's really true). I already have a RRA 20" std A2 and I was looking to build a really accurate upper which is the reason I'm looking for some help and advice. A lot of the stuff I've read is from the high power shooters who are always preaching about floating a good barrel. Problem is, they're always talking about Krieger barrels and Douglas barrels etc., etc.. These things cost like $700 ea. I think that's nearly obscene and I ain't gonna spend that kind of cash. I have noticed however that most national match rifles are of the heavy SS type. So what gives here? I do appreciate the help everyone! Thx

SS, chrome moly clean the same.  Chrome MIGHT be a little easier, but I don't notice any difference.

SS is more accurate... for target bull barrels.  For the types of barrels used for general shooting ("govt", M4, HBAR, A2, etc) there is just not a noticable difference between the three.

I like SS for its corrosion resistance, and chome lined for the same reason.  But I have several rifles with plain chrome moly barrels, and these shoot well, too.  

I doubt I will wear out any of these, as I don't fire full auto.  It is heat that damages barrels the most.

A 300 rnd battle pack, fired in 30-45 minutes would not likely harm a barrel.  It would be quite hot, but not really enough to damage the barrel.  Dump ten 30 rnd mags at full auto, changing mags as quickly as possible, and that barrel is trashed.

Remember, the MAIN reason for chrome lining was CORROSION resistance in rifles used in the very high humidity and rain of the jungles of southeast Asia when the M16 was introduced to our military.

If you want a good quality SS barrel, the Olympic Arms heavy barrels are excellent.  With the right loads, these barrels can shoot 1/4 moa.  I suggest just buying the whole upper already assembled.  The upper you want, with flattop, 20" ultramatch barrel, and free float tube, is their K6 for $630.00.  

It would be real hard to find a better barrel than the White Oak barrels offered by ADCO.  $233 for the Service Rifle bbl is dirt cheap for the quality.  $300 for the SPR ain't bad either.

This upper will mostly be used for target shooting and load development with and without optics (hence the flat top).

I'm not really sure what defines super accurate. Alot of that depends on distance and the type of load you discover for your rifle. Having said that, I'll likely end up shooting up to and around a  69gr bullet out to a max of about 300yds. I would like to think that 1/2 MOA would be about the best I could expect.

I have several of the Olympic Arms Stainless Ultra Match (SUM) barrels and have been very happy with them.  I have used some Armalite barrels and have had real good accuracy with them but they are as rough as a cob when they're new.  The Armalite barrels will take AT LEAST 200 rounds through them before they are to the point that the Oly SUM barrels are to start out with.  The other thing I like about the Oly barrels is that they are broach cut, not buttoned.  There is no stress added to the barrel.  When the barrel gets hot, it stays on target.  I have had buttoned barrels that would "walk" on the target as they  got hot.  That is the stress leaving the barrel as it gets hot.  When it cools down your POI is right back where you started.

Olympic Arms can be a pain to deal with but I have tried every barrel you can imagine over the years and the Oly SUM is consistently the best barrel I've ever owned.