Just got it from pyramyd two weeks ago. What a shooter ! Started breaking it in trying 10.34 jsb , 8.64 ftt , baracudas and 8.44 jsb. At first ( 100 shots or so ) it would not hold 1 inch groups at 25 yards using cross sticks from my back steps. It showed no real preference for any of these pellets. After about 200 shots it began to shoot better with the ftt pellets.I shot them for about another 100 shots over the next few days. The gun slowly but surely began to shoot good groups. The velocity finally evened out and was getting an es of about 8-10 fps for 5 shots. I was expecting about 10.5 to 11 foot pounds from this gun. It never did smoke or sound like it was dieseling and now it shoots the ftt 8.64 pellets at an average of 770 for 11.4 ft pounds ! I went back after 500-600 shots to the other pellets I had tried before and was delighted that it liked the 10.34 jsb pellets even better than the ftt pellets. (they are actually aa pellets but I know jsb makes them ) It shoots them average of 715 for 11.7 ft. pounds. I do not know why it shoots so strong but it is pretty hard to cock ( I am 70 and had shoulder surgery last December ) But I am using that arm to cock it and it is not bad just more than I would expect for 11.5 or so ft. pounds.The barrel is short though and that make a difference. The best news is that after just two weeks I have taken more pics with my phone of groups than I ever have before . Best so far was (all 5-shot groups) .44 at 39 yd., .68 at 50 yd., .75 at 60 yd., and 1.13 in. at 75 yd. I did not know a spring piston rifle was capable of shooting this kind of groups with me behind the gun. Keep in mind that these are the best groups I shot during a 10 day period with about 700-800 pellets. However it shot good groups when I did my part every time . These were just the very best of those. I am delighted with this gun and how close to pcp groups I was able to get.