Quote from: TexasInfidel on April 24, 2016, 07:43:56 PMI dunno,you tube and my recently Shadow(GTA) tuned Trail .22770 with 14's running 19fpeGuess its all in who does the fudging,some dont!EDIT: On the third reading, I think I finally realized that you may have mistaken my quote of "22.9J" for "22.9FPE". Even so, below is an example of my normal process - I don't have the atmospheric written down for when I hit 850, but I do have "0.073, 0.074, 0.073" written on my whiteboard. It's entirely possible I was dieseling.I have no cause to fudge, you don't know me from Steve. Feel free to math along if you like. I've taken it back apart since hitting 850, and it's cold, so it's a little sluggish this afternoon.My test is as follows: - Set recording microphone on rest - Set center of pellet trap precisely 35' from the microphone - Start recording - Shoot 3x from muzzle directly over the microphone - MathDistance: 35.0'Weather: 5.9C, 70%RH, 24.73inHg absolute pressure (speed of sound is 1098.42fps)Pellet: Crosman Premier UltraMag round-nose (14.3gr)Recorded durations between the end of firing and the trap strike for each of the three shots were 0.080, 0.079, and 0.081 seconds, so they (unfortunately roundly) average out to 0.080 seconds.To get FPS we first have to factor out how long it takes for the strike sound to get back to us from the trap. That's 35 divided by 1098.42, or 0.0318639 seconds. Subtracting that from the total time 0.080 gives us how long the pellet traveled downrange - 0.0481360 seconds. Speed is in feet per second, so 35 divided by 0.0481360 gives us our speed, 727.105fps.ft / (time - ft / speed_of_sound) = FPS35 / (0.080 - 35/1098.42) = 727.11fpsMuzzle energy = (weight * speed squared) / 450240(14.3 * 727.11^2) / 450240 = 16.79ft-lb 16.79ft-lb * 1.35582 = 22.76JIf you would like, I can email you the recording too so you don't think that's fudged. It's complete with the sound of me accidentally knocking the phone off the rest.
I dunno,you tube and my recently Shadow(GTA) tuned Trail .22770 with 14's running 19fpeGuess its all in who does the fudging,some dont!
Any FPE calculator will do it much faster then proving public school education long math727FPS-14.3gr = 16.79FPE so there isnt a 22+FPE NP2Use a real chrony and youll come very close to real world figures that do not support long math on PAPERThe NP2 is a sub 20FPE shooterRespectfully,