Do FDE rails help with heat?

[armakraut]

Do FDE rails help any with heat?

Either from the sun or the weapon itself?

[orionz06]

From the sun, technically, but you would need to know the emissivity of a black anodized rail vs a flat dark earth anodized rail. That being said, it is likely there is minimal difference from the color alone. Hot will be hot when there is a large difference from ambient or your skin, cold will be cold when it hasn't been fired.

[armakraut]

I remember threads from a couple years ago where competition shooters were painting their viking tactics rails FDE or OD in an effort to mitigate the effects of the sun on the rail. The sun out here is horrible, makes the guns hotter than hell even before they start shooting in the middle of summer.

[orionz06]

Painting is a different animal. Anodizing and paint will radiate heat differently, and some white paints will get as hot (or hotter) than some black paints. Anodizing, IIRC, gets pretty hot regardless. I will have to look at a heat transfer lab from a few years ago where I dabbled in almost this exact question.