I have backed off the spring tension as much as possible in my magazines so they grip each pellet less tightly, but the pellets are getting a bit damaged. Certainly, if I push JSB clones (AA Fields or Daystate FTs) though the magazines with a pencil or similar, I can see marks on the edge of the heads and skirts. Harder pellets such as H&N Baracuda or Bismags don't seem to be effected as badly, but I prefer the flatter shooting JSBs.
I think if the pellets are being damaged, the accuracy difference will only be evident over longer ranges -but that's when the wind steps in and confuses everything! Maybe someone has done some definitive long range testing in a wind free environment?