Bought some seals from the Russian federation on a while back to cure a very slow leak on my Baikal Makarov only to find that the seals where a bit hit and miss with some breaking with very little effort and loads of flashing on the seals as if they were cast from a mold. In the end i used some normal small O rings that done the job quite well i did replace the seating washer with the clear plastic seal supplied but it was a pig to remove, the old one seem to be made of white hard plastic. I thought in future it would pay me to buy a box of small assorted pack of O rings in a box and buy some special ones for the valve seating which is different to the rubber O rings and the same for the seal for the Co2 gas bottle. What type of material is the white or clear valves seals made of and can these be bought off the shelve as per normal O rings. I rather buy quality seals than cheap crap (saying that they were not cheap). Anyone use an alternative, what do you use.