I could be totally offbase here, but it sure would seem the HBAR would be more accurate than the lighter weight, and therefore skinny, Govt. profile barrel. Sort of off subject, but I have a Ruger M-77 with an HBAR in .22-250 and it drives tacks.

The consensus seems to be that both barrels perform about the same, and that the Govt. profile is lighter and more desireable as a result. Per a previous post of mine, I ordered a Bushy M4/A3 with the Govt. profile barrel and received an HBAR instead. I posted about it to get some advice and most folks said to take it back in favor of the Govt. profile. I did so, and am wondering now if I just sacrificed some accuracy in favor of the Govt. profile. Any thoughts...

It is exactly 0% more accurate.  I can understand your thinking th HBAR would be mre accurate but per your own words you have been corrected in your thinking and yet you caome and ask the same quaetion again?  Why?

From a cold barrel, with a single shot there would be no difference.  But as barrels heat up they grow and move around, therefore your accuracy will be affected.  Is this measurable, I don't know, but almost all the precision shooters use heavier barrels.  That should tell you something.  Yes, it is a stability issue due to the weight of the barrel, but it also a heat issue as well.  Heavier barrels heat up slower and cool down slower, therefore they are more stable through a string of shots.

DCM/CMP rifles all have heavy profiles.  The weapons used in the military intended for precision shooting all have heavier profiles - SPR, SAM-R, RECCE, M24, etc., etc.

Heavy barrel is not te limiting factor its the bore of the tube.  If you dotn have a match grade barrel there is no reason to go HBAR.  chrome lined military style barrels have no reason to be HBAR in an AR15.

May I expand the topic slightly?  My "M4" barrel is turned down under the handguards.  In this area it is about the same diameter as a lightwieght, or pencil, barrel.  That is the hottest area of a barrel.  What effect does the extra steel foreward of the FS have?  It now seems to me that I should have just used the thin barrel for this build.  I have no use for the M203 cut.  Does this barrel profile have any other reason for being around?

In all of my ARs-HBARs, gov profiles, M4 profiles, CARs, chrome lined vs not, or 4140 vs 4150 either the ammunition or my own shooting ability are the two factors that most hinder my accuracy.

From a practical standpoint I can't tell the difference in accuracy between a 20" HBAR and a 20" gov profile. There certainly may be some mathematically quantifiable difference, but for the distances I shoot (0-300 meters) I'll be damned if I can see it.

I am a competitive service rifle shooter and my main reason for a HBAR is to reduce barrel whip and vibration.  It also helps keep it consistant when I go from shooting a slow fire, then spend 2 hours in the pits, then go and shoot 2 rapid strings back to back.  Every little bit counts when trying to keep shots within a 6" circle at 600yds for a perfect score.

Every little bit counts when trying to keep shots within a 6" circle at 600yds

Cripes, I don't think I could even see that target without massive optical magnification

Like I said that cant be done with a chrome lined HBAR nor govt profile barrel.  You are AGAIN talking about match chambers and match barrels.  Big difference.

Quoted: Every little bit counts when trying to keep shots within a 6" circle at 600yds Cripes, I don't think I could even see that target without massive optical magnification

That's why they invented the ACOG

Quoted: Quoted: Every little bit counts when trying to keep shots within a 6" circle at 600yds Cripes, I don't think I could even see that target without massive optical magnification That's why they invented the ACOG

Amen to that