Not worked it out yet.
Same gun, we've tested long, short, medium. What appears to be the case (and it's really early days) is that some barrels prefer a shape of pellet, and some prefer others. I've got one pellet which goes well in all, but I'm waiting to see the variation across batches before saying it's wonderful.
BC is what gives you the wind drift, but i'm not seeing any correlation with precision, just accuracy. The worse the BC, the worse the drop. But in reality it only adds about 1 MOA to a group. However between the best and worst of a pellet I've seen 2 MOA at 55yds.
So I think it's more to do with shape, shape giving BC, and shape fitting the barrel.
Between the barrel brands there is a lot of variation in the shape of the lands and grooves. And also the tightness of them, and that tightness relative to the choke.
Theories. All good fun.
Your English seems pretty good. But we do excuse the Midlanders a little anyway