Barrel fluting: yea or nay

[lysanderxiii]

Why are these barrels fluted?

M242 Enhanced Bushmaster:


The original M242 Bushmaster barrel used to look like this:


Well, because the original unfluted barrel was found to have notable whip which effected dispersion, and during sustained firing got hotter than desired. A new chrome lined barrel was developed to address these problems. The outside diameter of the barrel was increased and fluted. The added mass of the barrel increased the heat sink capabilities of the barrel, the larger diameter makes the barrel stiffer (which helps the 'on-the-move' accuracy as well as reducing dispersion along with the new muzzle brake design), and the fluting helps reduce the overall weight of the barrel (but, it's still considerably heavier than the original barrel).

Again, you can argue whether, or not, the magnitude of the benefits a fluted barrel brings to the AR-15 or target rifle are worth while, but the three things noted at the end of post #19 will always be true.

 

[mshootnit]

I have read almost all of each post, thanks to everyone for the thoughtful information.

 

[DRYHUMOR]

More material equals more rigidity. With a given weight, a fluted barrel will flex more than one not fluted.

A fluted barrel will release heat faster; though an un fluted one will gain heat slower.

A good barrel will shoot well, fluted or not.

 

[lysanderxiii]

. . . though an un fluted one will gain heat slower . . .

Not necessarily.

How fast the barrel temperature increases solely depends on the mass of the barrel and where that mass is.

A regular AR Government profile barrel will heat faster than a fluted HBAR profile barrel.

A fluted HBAR profile barrel will gain heat faster than an unfluted HBAR profile barrel, however, the fluted barrel will radiate heat faster, so the actual temperature may be fairly similar, depending on the actual increase in surface area from the flutes.