I recently purchased a Disco tube, and when I went to install the valve found out that the hole for the transfer port, and the two 4-48 holes for the middle breech screw, were drilled about 0.028" too close to the back end of the tube.... The port in the valve didn't line up, and the breech screw hole was far enough off there was no way you could install a breech.... Fortunately, I had to enlarge the transfer port hole anyway, and I was doing a custom breech, so I drilled and tapped a new screw hole in between the originals and will make the breech to suit.... Without modification, this tube was unserviceable, but somehow made it through Crosman's QC....
Bob
Reply With Quote
It's okay for the cup piston and factory plastic block with ovalized holes, but for a flat top with one of the old "Crusty" brass pivot blocks, it's a total no-go. I'm pretty bummed over this. I had wanted to shoot it tonight with the little Weaver I had picked up Saturday. I'll give it another shot tomorrow- try and get a 24" bbl 13-77 that isn't holding, up to par...