I got my Wildcat in .25 cal. about a month ago and have about 500 pellets through it so far doing pellet testing. I shoot left handed and recently noted a puff of air against my face when shooting. I have not tested it so far to see if it is shooting with less fps or changing the impact point. It must be the internal barrel o-ring at the breech end of the barrel and of course I would like to replace the o-ring. According to the parts list for the .25 caliber it is part #4526 and is an 6.35mm x 1.27mm NBR70 o-ring. In researching the various o-ring for the Wildcat some can be found in the metric sizes and other sizes listed can be found in an equivalent size off the AS568 o-ring chart. This o-ring seems to be a off size with a small cross section of 1.27mm or .050" or 3/64". The closet I can find is a #010 which is 1/4" ID , 3/8" OD, .070" CS would this work?. It seems that other FX rifles also use the o-ring #4526 in their .25 caliber rifles and with my recent experience others must be replacing this internal barrel o-ring fairly often. Is AOA the only place to secure this o-ring or can they be bought somewhere else. Any help would be much appreciated. Bill