A new TX200 with H&N .177 8.64 gn pellets. Front (left) hand rested on a bean-bag, open-palmed. Butt pad into the right shoulder, ten shots at 20 yards, pellet on pellet, or sub 10mm group. At the time wearing a padded jacket. Remove said jacket, same process, same size group about 10-12mm higher than that with my jacket on! Just a T-Shirt between me and the rifle. I wasn't holding the rifle too hard into my shoulder. Interesting to see - explanations welcome!