If you don't mind upping the brightness on your CRT a bit, in theory a guncon2 gun with the guncon driver can track all the time (issues on dark areas - so would need more brightness/gamma in games like T2).
Not tried it myself, just read other peoples posts, but it was what caught my attention about the pc driver - apart from positional guns its the only realistic way I see of playing games with a gun that need to be able to hold down the gun. (T2 with an actlabs is v hard - you have to hammer the trigger, whereas the game is designed for continous machine gun fire.