I just started noticing this. The manual and dye techs both say the nt11 needs to operate at 120-150psi, which I obtain by green insert, green spacer and operating perssure at 125. However I know that for the longest time I used just the green tip insert with no spacers operating at near 105. I dont know how to fix it back. Ive changed all the orings with no luck. I would have thought that the orings would have broken in but doesn't seem like the case for me. However there is a notable increase in sound and the shot is a bit harder too.