Fluted barrel

AR/M4 AR General Discussion
1

What is the reason behind a fluted barrel?

2
  1. More surface area to cool quicker
  2. Stiffer
  3. Lighter
3

The ‘stiffer’ part benefits from a little more explanation. A barrel is less stiff after fluting than before, but it is more stiff than if an equal mass of material had been removed by turning on a lathe.

4

Good explanation.
In order for a barrel to be stiffer and of the same weight, the fluted one would have to be larger in diameter.

So, taking two barrels of the same length/diameter and fluting one of them will leave the un-fluted one stiffer, but also heavier.

The only way to make a barrel stiffer is to shorten it.

5

The con to this is that a fluted barrel has less mass, so it heats up faster.

6

So revised it would be:

  1. More surface area to cool quicker vs. same weight non fluted barrel
  2. Stiffer vs. same weight non fluted barrel of the same length
  3. Lighter vs. same diameter non fluted barrel of the same length

Thanks for the corrections

7

It works both ways.
Less mass heats up quicker and cools quicker.
Heavy barrels heat up slower and cool down slower.

I’m of the opinion that the MASS of the barrel is more important to how fast it heats/cools than the surface area.

So, take a govt profile barrel and a fluted barrel of the same weight.
They both heat up and cool down at very similar rates.
The small increase in surface area makes an insignificant difference in cooling rate.

8

Thanks everyone, now I can understand. I"m just doing my homework for my first build. Can’t wait to get started. John

9

Thanks for making my fluted barrel seem silly! I always thought that the fluting was an advantage.
I guess it still has the CDI factor but since I am an old married guy who cares…