Hi all, I have a 1980's vintage BT-99 that doesn't eject at the range. I've shot trap with it twice and the first time it ejected maybe ten of one hundred rounds. I kept one of the empties and tried it at home and it ejected every time I tried. I thought maybe I wasn't opening the gun fully but paid attention to that today and it didn't eject a single shell. Tried at home again and it works fine. Any ideas?