Light gun calibration question

[AlanS17]

I've got 2 light gun calibration questions:

(1) Do I need to recalibrate every time I restart the computer?
(2) If I force a resolution (like 640x480) for every game, do I still have to recalibrate when I start a newgame?

[u_rebelscum]

I've got 2 light gun calibration questions:

(1) Do I need to recalibrate every time I restart the computer?
(2) If I force a resolution (like 640x480) for every game, do I still have to recalibrate when I start a newgame?

(1) No.

(2) If you force the same screen size and same refresh rate, then you don't need to recalibrate.  
If you force the games to run at the same size, but let them run at different refresh rates, you'll need to recalibrate when you switch from a game that runs at one rate to one that runs at a different rate.
And if you want to use the guns on the windows desktop, that's another recalilbration, unless the desktop and games are run at the same resolution (size + rate).

FWIW, I force one screen size, like you asked.  I my experience, recalibration takes under 10 seconds, and I rarely cross from a game with one refresh rate to another game with a different rate.  So I don't need to refresh that often.  (But I usually go thru "phases", at least AFA lightgun games go, so you might "cross" refresh rates more often.  You can force a refresh rate, but you might run into display, or even emulation, problems depending on the options you set.