Hi guys: Generally speaking is heavy barrel more accurate than a M4 type barrel? Would a 16" Bushmaster heavy barrel be more accurate than a 16" Bushmaster M4 barrel? I am trying to put together a new upper just can't decide which barrel to order. Also would a Fluted 16" HB be lighter than a 16" M4 barrel?  Any help would be really appreciated!  Thanks

HBAR is no more accurate than an M4 barrel - just heavier.

From Lightest to Heaviest:
Lightweight 2.0 lbs
M4 2.2 lbs (either 16" or 14.5 + longer muzzle device)
Fluted HBAR 2.3lbs
HBAR 2.7lbs

"HBAR is no more accurate than an M4 barrel - just heavier"


That's an oxy-moron Heavier means less vibrations, means better accuracy.

esspecially as the barrel heats.  

For some reason there are people who believe that there is a free lunch out there (there is not- If you want the best accuracy you will have to use the heavier contour barrel.)

[b]The accuracy difference is probably 1MOA for the M4 and maybe three-quarters to half that for the 16in HBAR.

Both figures for free floated setups (without a FF HG your groups will depend on forearm tension and consistency.)

Not a big difference as neither barrel is match grade and both are chrome lined. But a difference nonetheless[/b]

How about the 20" barrels?  Is there a .5 MoA or more difference between 20" Govt A2 and HBAR?  

thanks a lot guys! I think I will go with a M4 barrel because my lower is semi and even with a fluted 16" HB it is still a little heavier than a M4 profile barrel.  If the accurate difference is only 1/2 MOA I can live with that.
Thanks again!!!

I just dealt with this issue.  I initially had a Colt 16" HBAR that was just too heavy for its intended purpose as a patrol rifle.  I sent it to Kurt's Kustom and had the barrel turned and fluted.  There was weight savings of ~5 oz or 1/4 lb.

As I run a Surefire M500AB, that wasn't enough weight savings.  I ultimatley bought an M4 upper and found it to be ideal.  I shot both side by side and I did not notice any appreciable difference in the accuracy of the two units.  I fired ~3,000 rounds between two carbine classes and never had any concerns with heat or accuracy.  Pat Rogers made the point that while the HBAR heat more slowly, they also cool more slowly.  You're actually more likely to have cookoff with a heavy barrel than an M4.

P.S. - For anyone interested, I have a nice, hardly used Colt HBAR upper with a turned and fluted barrel.