Had mine back to the dealers I bought it from today, and it's not as bad as I thought ! They chrono,d it on a skan chrono after weighing the pellets so they were all the same, ( I won't be buying another tin of jsb jumbos , they were anywhere from 15.8 up to 16.9 ), tested it with 10 weighing 16.2 and it's putting out 10.78 , also done 10 f.a.p which were excellent on the scales, all either 13.7 to 13.8 although the tin states 13.4 , results were also on the low side, dealer spoke to day state and it's on it way there now for a full service , tune up all free of charge, I was using a combo mk4