Got 1 of the fx screw on tuners today and while I haven’t shot it much am a bit surprised just how much affect it has on pellets in 177 at 10 meters. It only moves front to back around 1/4” but just installing on my 500 mm barrel changes point of impact about 3/8” right and 3/8 low. This is with a carbon sleeve and the barrel tensioned with the shroud. Can’t wait to see what it will do at 55 yds! Will try to post more results when i get a chance to shoot with it at distance