I had an interesting occurrance of the 'one barrel one pellet' phenomenon on Saturday. I was rechecking the settings on the Dommie, when I decided to switch from JSB to FX.
I've had the tin of FX pellets for about a month but never got round to testing them. Now this was't a scientific test but more of a lets see what happens test. Both the JSB's and the FX's are 4.53. Of a rest they, surprisingly, shot to the same point of impact but with the FX's printing about 35mm to the right.
I didn't have the time to investigate any further, so I returned this afternoon. This time I shot 10 shot strings from a sitting position again at 50 meters, indoor i.e. no wind, 6 strings of each, alternating between the two.
The JSB's shot consistently to about 35mm ctc, I could keep the outer edges in a 40mm circle - the odd pulled shot excepting. The FX's would string horizontally about 90mm x 40mm.
Now the FX's seem to be very well made pellets so the only conclusion I can come to is that my Dommie doesn't like FX pellets.
Next I'll try both the JSB's and the FX's in the Cheerleader's CZ 200, she normally shoots Ultratec's. I'll post the results.
ps: If anything, this proves that if pays to try different pellets until you find the pellet that works best in your rifle.