I did get some chronograph data last weekend (after losing a couple of strings to human error).
They started at a lower velocity and climbed in velocity, then dropped toward starting velocity, I'm assuming this is expected with non-regulated PCP. the velocities were somewhat lower than I expected from the factory tune, they started in the high 700's/fps for Jumbo 15.89 gr. and mid 700's/fps for HN18.21 gr.
I'm wondering if my gauge on the rifle might be out of calibration, when the rifle reads 3,000 psi the gauge on my Hatsan compressor is reading just over 2,000psi. when the gauge on the rifle dropped just below 2,000psi my velocities dropped severely down to the 500's/fps. Groups with the JSB were pretty good 10 shots coverable by a dime @ 25yds, the HN were not so good 10 shots bigger than a quarter @ 25yds.
chronograph data was taken @ 5ft. from muzzle.
View attachment Book1.pdf
They started at a lower velocity and climbed in velocity, then dropped toward starting velocity, I'm assuming this is expected with non-regulated PCP. the velocities were somewhat lower than I expected from the factory tune, they started in the high 700's/fps for Jumbo 15.89 gr. and mid 700's/fps for HN18.21 gr.
I'm wondering if my gauge on the rifle might be out of calibration, when the rifle reads 3,000 psi the gauge on my Hatsan compressor is reading just over 2,000psi. when the gauge on the rifle dropped just below 2,000psi my velocities dropped severely down to the 500's/fps. Groups with the JSB were pretty good 10 shots coverable by a dime @ 25yds, the HN were not so good 10 shots bigger than a quarter @ 25yds.
chronograph data was taken @ 5ft. from muzzle.
View attachment Book1.pdf