Sharing some testing I did with 4.52mm FTT pellets shot from my Air Arms s400 MPR. I got this gun used and it has been tuned up from it's original 10m configuration. I have turned down its transfer port restrictor so the gun is shooting at about 12 fpe which is down from the 14-15 fpe in the configuration I received it in. (I could not get the gun to group well at that higher power.)
The BC I came up with was 0.018.
This is a bit lower than the 0.021 BC they advertise. I used Chairgun's BC velocity difference tool to come up with this number. For reference, here are the numbers I got and used for this calculation:
MV = 793 fps (5 shot average)
Far velocity = 582 (5 shot average)
Distance between speed measurements = 49 yards
Elevation = 1300 feet
Temperature = 70f
The BC I came up with was 0.018.
This is a bit lower than the 0.021 BC they advertise. I used Chairgun's BC velocity difference tool to come up with this number. For reference, here are the numbers I got and used for this calculation:
MV = 793 fps (5 shot average)
Far velocity = 582 (5 shot average)
Distance between speed measurements = 49 yards
Elevation = 1300 feet
Temperature = 70f
