Colt 6940 Heat dissipation

AR/M4 AR General Discussion
1

I am noticing a problem n my 6940. It seems like the built in rails do a terrible job at dissipating the heat from firing. I have had quad rails before but for some reason this one seems much worse than any of the others. Is this a side effect of the Monolithic Rail system or something else, like me being a pansy?

I also noticed that my Aimpoint is very hot to the touch so the heat is transferring through the mount all the way up through the site. It is much worse than on my other rifles. 200-300 rounds it it gets noticeable. 500+ rounds it gets uncomfortable and around 600 rounds it was getting painful.

Advice? Observations? Criticism?

2

That’s odd… one would think that a one piece aluminum rail would act as a more effective heat sink. Interesting…

3

Sounds like it’s acting as a very efficient heat sink. It’s drawing the heat away from the barrel very nicely. :smiley:

Either you need better rail panels or better gloves (aka "Chicken Mitt).

4

My thoughts exactly.

5

6

But that makes mag changes tougher. :rolleyes:

7

HAHAHAHAHA F2S. Aren’t you just funny. (Actually yes you are)

I just use Ladder style covers. I guess that really is the difference. I have always used panels before. I have some XTM panels but they are pretty wide when put on the 6940 rails. In addition they don’t want to fit right on the bottom where I have my VFG. Maybe I will pick up some XT panels that I can cut.

8

That is Fn great

9

Wait, is that tactical enough?

10

Here is the answer you seek young Padawan…

11

Arn’t the knights rails pretty thick?

12

They are among the thinnest of all the rail covers. Supposedly, the new SCAR covers are thinner, but I don’t know of any others.

Some claim the XT/XTM are thinner than the KAC’s , but they don’t feel thinner in my hands.

13

Isn’t insulation pretty much the opposite of dissipation?

14

Yeah I worded the title badly. Heat is being dissipated away from the barrel, however it is going strait into my hands and the optic. I even noticed very prominent heat distortion through the optic after about 3-400 rounds and I am not used to that.

15

I know PK firearms used to have a magazine body with a fan [batt,& switch] wired into the magazine body you inserted it into the rifle with the bolt locked back and it would blow air through the chamber. I checked there web site but I cant find it anymore:(. Seems like that product may help the OP with his problem.

16

Your Aimpoint can take the heat, don’t worry about that…but yeah, you should get some decent rail covers.

17

Problem solved. I removed the XT panels from my 9MM gun and put them on this gun. They are a bit thinner than XTMs so I prefer them on the wider rail. Now the ony problem is my XTMs don’t seem to fit right on my Troy Rail on the 9mm.