At my work Shooters Bench we believe we’ve found a fix for the Brococks that are blowing the Orings off the fill probes when filling them. Our air gun smith measured the factory Oring for proper fit. We ordered a replacement of a more firm rubber, see pics. They are rather difficult to install due to there material they are made of. They tend to break, only stretching so much. We made a simple little tool that makes it a breeze. It’s basically a awl that is cit off at the exact diameter as fill probe that retains the Oring and spring. Applying high end 100% silicone the Oring slides down the taper spreading over the probe into place. I’ll try to get pics of process ASAP if it will you all. The Brococks we’ve replaced with these Oring have not come back with this problem. Hope this helps
