Ok in my opinon here is your mistake using bore butter with a saboted bullet thats a no no.Try just shooting the gun untill the bullets are hard to load,which should be at least 5 shots ,I can shoot all day without cleaning I use 200 gr hornady with high pressure sabots.I don' t know what the weather is like there so try and shoot with the barrel cool.If you are using a scope don' t keep adjusting it over and over,get the gun to shoot right than adjust your scope or sights acordingly.hope this helps.