PDI Hop-up Chamber For The Maruzen Type 96 - Changing The O-rings

After one (1) year of un-shakable usage and performance, I thought it is time for a change-over of my 0-rings, since I could not get my velocity up. In fact, I had a 50 FPS DROP when I changed my pistonhead. It was a combination of multiple problems! And it wan't my port-and-polish of my K2 all steel cylinderhead. It was the nozzle not being able to enter the hop-up chamber for a good nozzle seal. It probably was caused by slam-chamber when I got pissed off at my rifle when my bolt couldn't lock back.