I'm new to the Airgunnation forum. I'm reading this post as a reference for tuning my Redwolf and I'm sorry to hear about Mark's passing.
I have a few questions and need help to resolve them:
1. Once I've established my target velocity, for example 970 fps, how do I determine the low pressure point? Is it random, for example 180 bar, 190 bar, 197 bar, 160 bar... and starting from that pressure, chosen at random, tune my RW determining the pulse length and voltage to achieve my target velocity, or is the low pressure point determined by the pulse length and voltage that I have by factory default in the rifle as the lowest bottle pressure that reaches my target velocity?
2. Following the reasoning of point 1, once the low pressure point is established, is the mid pressure point random or is it determined as the mid point of the 250 bar-low pressure point interval? For example, if the low pressure point is 190 bar and the high pressure point is 250 bar, is the medium pressure point 190+ (250-190/2)= 220 bar?
3. Once the low, medium and high pressures have been established (I assume 250 bars), should the pulse length be the one that always gives me the target speed or as close to it as possible (for example 970 fps) or just above 970 fps?
I hope my questions are not too confusing.
Thank you very much for your help
Hey there! I'm in the process of programming my Redwolf .22 High Power using JSB 25.39 RD. I'm not an expert so if some else knows more about this, please correct.
I'll share some information that the folks at Airguns of Arizona passed on to me about tuning these pellets for 970 fps, which AoA said that I should be able to get 50 shots with an ES of 15 - 17 fps.
Question #1 - AoA recommended setting the low pressure point to about 180 bar, then adjust the pulse length to get the velocity. From what I understand, voltage is how hard the hammer hits the valve, pulse length is the duration of volts. Don't set the voltage above 70 and AoA recommended 68.8 volts. My Redwolf was programmed with volts at 69.96 when I got it, so I left it there.
I'm thinking that at some point, increasing the pulse length would no longer have an effect on velocity, so you would need to increase the pressure if you're not at the velocity you want. But this is an assumption on my part. This will be your low pressure point/pulse length.
Question #2 - Find the pulse length you need for the high pressure point of 250 bar to reach the velocity you're looking for (which should be the same as the velocity at the low pressure point). I currently have set the mid pressure point as you've described above (250 + 180)/2 = 215.
Question #3 - Setting the mid pulse length is where I discovered, at least for my Redwolf, something interesting. I initially set the mid pulse length to give me my target velocity at 215 bar, but that resulted in a "hump" in velocity in the middle of the shot string. I had to reduce the mid pulse length to flatten the curve, which resulted in a lower ES over the entire shot string. So for my rifle, the mid pulse length needs to be closer to the low pulse length than the high pulse length. Using this equation, (High Pulse - Mid Pulse)/(High Pulse - Low Pulse) = X, I found where X = about 68% would result in a flat velocity curve.
Right now, my average velocity is 950 fps with an ES of 18 fps over 50 shots with JSB 25.39 RD straight from the tin, no sorting. I'm thinking sorting will help reduce the ES as my velocity curve trend line is flat across the shot string. I'm now adjusting my pulse lengths uniformly (add 50 to each, take away 50 from each, etc.) to find the most accurate velocity. Then I'll start sorting pellets.
Again, I'm no expert, so take this for what it's worth and if someone knows more, please share as I would really like to learn more.
Noah