I had a problem with my Volquartsen pistol. It would not cycle SV ammunition and some magazines were very difficult to extract. VQ offered to send a new bolt, but I had to return the old one first. Turns out that neither Canada Post nor any courier company would knowingly ship a gun part to the U.S.
Eventually I contacted Sylvester Sporting Goods, which is listed as an international distributor on the VQ web page. Todd, of SSG, immediately replied and assured me that he would take care of it. It took a while because the shipment from VQ was very slow in arriving. In the interim I emailed Todd several times and he always wrote back right away to advise me of the progress. Since there's little, if any, profit in this kind of warranty service, it would have been easy for SSG to ignore this problem. But Todd stayed right on it and maintained prompt contact all along. I think that kind of good work deserves public acknowledgement.
BTW, the new bolt basically resolved the problems. Magazines eject cleanly and cycling is much improved. The gun is still a bit picky about some brands of ammunition, but no more so now than many .22 semis.