I had did some shots on my hdp 50 compact today and it seems to shoot good, I had some issues with trigger sticking at first and used some silicone spray to lube it and it's better, I have seen videos where it hits 420ish on first few shots than drop to around 400 upper 300sfps on second load then it drops alot by 15th shot, it's suppose to be a lil stronger than hdp 50 unmodified, I hope mines hit 420, idk because I don't have a chrony but it was loudest on first 8 shots then it was getting weaker on 10th shot, great gun if working properly, Id say after 2 refills it's not gonna have much power after!