Previously, I had tuned my .25 Avenge-X tank version using AEAC Steve's method for JSB 33.95 MK2 pellets at 870 fps and it worked very well. Now I am playing around with JSB 25.4 grain pellets mainly to get more shots per fill since I am only shooting paper. I went thru a tune using Steve's method first and I seemed to get about 90 shots before the tank got below the regulator setting. I was trying for 910 fps for those pellets.
Yesterday, I went thru the process of "tuning to the knee". First time I have tried this method. I set the regulator so that the plateau fps was around 940, then adjusted the hammer spring down so I was getting about 900. (I was trying for 910) . With this tune, I get several more shots but it doesn't seem to be as stable as with Steve's method. Accuracy is good but I am only shooting 30 yards in my back yard. I have attached a graph for the whole shot string down to tank pressure of 100bar and a subset of the first 100 shots. Any advice on Steve's way vs the "tune to the knee" way? I plan on re-doing to get close to the 910 fps which is supposed to be optimum for the 25.4 grain JSBs.
Yesterday, I went thru the process of "tuning to the knee". First time I have tried this method. I set the regulator so that the plateau fps was around 940, then adjusted the hammer spring down so I was getting about 900. (I was trying for 910) . With this tune, I get several more shots but it doesn't seem to be as stable as with Steve's method. Accuracy is good but I am only shooting 30 yards in my back yard. I have attached a graph for the whole shot string down to tank pressure of 100bar and a subset of the first 100 shots. Any advice on Steve's way vs the "tune to the knee" way? I plan on re-doing to get close to the 910 fps which is supposed to be optimum for the 25.4 grain JSBs.