Got some time this evening to do the testing of the valve with the groove filled in with JB Weld.... As expected, there was a slight gain in performance, but the efficiency has pretty much leveled out.... Here are the results....



The interesting thing about this version is that the performance at mid-preload settings continues to improve.... The best shot strings are now happening at less preload than before.... I got 19 shots within 4% with the JSB Kings, 971-1007-968, averaging 992 fps (55.5 FPE) at 1.13 FPE/CI, filling to 200 bar and shooting down to 133 bar at 6 turns of preload.... The best strings with the H&N Baracudas and the EunJin Domes were at 6.5 and 7 turns of preload respectively, and returned 16 shots....

I shot a few pellets at 8 turns of preload, and the velocities were peaked pretty much at 200 bar for the lighter pellets and 180 for the heaviest.... The maximums recorded were:

25.4 gr. JSB Kings - 1046 fps - 61.7 FPE
30.9 gr. H&N Baracudas - 982 fps - 66.2 FPE
35.2 gr. EunJin Domes - 939 fps - 69.1 FPE
41.7 gr. EunJin Pointed - 881 fps - 71.9 FPE

I think there is a bit more in the gun yet, I could enlarge the valve throat a bit more and slim the stem.... and then I might have to make the inlet side of the valve breathe a bit better as well.... If I do that, I will then have to restrict the transfer port to keep the velocity under 1000 fps with the JSB Kings.... so I don't know if it's worth it....

Bob