Josh B I went to Gary's and shot his QB78s. Had midway USA gift cards from the girls for fathers day and bought 2 QB78s, one had bad seals from the factory. I have very good service from Flying Dragon Air Rifles. He completely disassembled cleaned and replaced all seals and shipped it home for less than $50. That was a few years ago so my be more now but I talked to the guy on the phone and he was first rate. call and talk to him see if he works on the Sheridans.