Diagnosing long range errors: Bad RF?

[yobuck]

Dont need no steenkin rangefinder.
Easy as one two three.
Guess the distance.
Send one over there.
Dial to the hit.
Write it down for next time.

 

[Hugnot]

Temperature will affect laser wave length.
Temp increase - laser wave length decrease. Temp decrease - wave frequency oscillation slows & wavelength increases.
This can mess things up. Dust & other stuff is bad also. Best to combine common sense with info shown on range finder.