I'm in the middle of tuning my sons .177 Maximus and I've come across something interesting. I slapped a few o rings in front of the valve and I am in the middle of shooting my first string. The o rings dropped the velocity down from 1100 fps first shot to 774. The shot string is still at a steady decline in velocity, but much slower. I've taken 26 shots on this fill with a high of 780 (second shot) and a low of 721 (shot 26). The impressive thing is I've only used 200 psi of air for 26 shots. My son is more than happy with this power because he'll get more shots per fill. My question is how can I reduce my extreme spread? The first 17 shots have a 20 fps spread with no curve and then they fall off. With this many shots using so little air, there has to be a way to get more shots per fill with a tighter extreme spread. I'll finish shooting the string down to 1000 psi after I feed the animals (kids).