Got a rotatry magazine fitted to an Alros, the type with a big o ring stretched around its perimiter, to hold the pellets in place. Bolt a tad jurky when pushing forword to load a pellet, never gave it much thought, thought it was part and parcel of the design. That was until I cycled it through without the barrel in position. The pellets came out with a very pronounced groove cut into them as they were pushed out of the mag. De-burred the holes that caused the cutting, and now it loads and shoots like a dream.
Running a gun through its loading sequense without the barrel, is a good way, to check that non of the pellets are getting knocked about before they are fired.