NO TIME !!!Bob
I like the way you have laid this out so people can understand the dynamics of the importance of Matching striker momentum to the pressure and output so it is in sinc.I have tuned the Regged guns similarly lately & with the addition of the transfer port restrictor to the set-up you outlined, you can see a noticeable shot count improvement and also have the benefit of keeping the velocity from increasing as it comes off the reg.We can change hammer weight and spring tension as well as port flow. That control is important and is why an external hammer with a threaded boss for adding weight is a key tuning feature!.TimmyMac1
My thought is if I could get my velocity to be 815 fps avg on the reg I should get a very small increase when it falls off the reg that would climb to the 825 fps and start back down to 815 fps. Is this correct?
If you further reduce the hammer strike, you are now operating on the "downslope" (eg. at 6 turns out on the previous graph).... The velocity is significantly lower, and as the tank pressure drops, the velocity usually shows a slight rise until you hit the setpoint (due to regulator creep), at which point it then increases significantly before dropping off.... The peak of that bump in the velocity is where you have now tuned the gun to if it were unregulated, in this case 1200-1300 psi.... While the gun is shooting above the setpoint pressure, it will be VERY efficient, with virtually no chance of hammer bounce occurring, and this is a good tune for target shooting, or something like FT, with one exception.... that jump in velocity below the setpoint.... If you are competing in a class where the FPE is limited and have the gun tuned for, say, 19 FPE when it is above the setpoint and they check your velocity at the end of the course and the pressure is below the setpoint you could be over the allowable FPE level.... It could also cause you to start missing targets due the increase in velocity you weren't expecting....