Quote Originally Posted by Shed tuner View Post
A leak ?
Hmm, what like a weak shot at the start of the string, then it improves seals towards the end of the string, then repeats after the interval when changing the mag?

Interesting thought. If the peaks are joined up, the trend is in the right correction (reducing velocity/power), but the saw tooth ramping velocity up while pressure in the cylinder reduces is counter intuitive.