I have no real trouble believing all the comments made on here so far but wonder if there is anyone willing to conduct a small experiment?
With your choked rifle, shoot 10 x 10 shot groups at say 30 yards, preferably bench rested to get the best accuracy and consistent conditions. Do this with maybe 5 different pellet makes. Record the individual pellet strike parameters for each 10 shot group as mm displacement from the 'bull point'.
Now remove the choke on your rifle and repeat the process.
It would then be possible to analyse the data obtained to see if there was a difference between the choked and unchoked barrels and whether the results were consistent over different pellet makes. Proper statistical analysis would be important. I think using different pellet makes is important as removing a choke may well influence individual pellet make performance more than other makes. But this is only my thought; I have no evidence.
Of course, such an experiment will not settle the debate in its entirety but may well give at least a preliminary insight to what can happen.
Cheers, Phil