I have a black delrin bolt (shouldn't that read 120 ish)
and when the bolt is pulled all the way back it still only reads 115!!
It appears to detect paint, but when shooting with the eye on it just holds the bolt back for whatever the pre-set time is and then completes the cycle before shooting the paint!!
*bangs head on wall*
Edit:---
Just noticed another problem, may be connected, when I check the battery power it says LOW, before displaying the true power (in this case full as its a new battery, have tried 3 duracells now)
*bang head on wall some more*