1) Brittle paint - A5 chops high grade paint. Use cheaper one.
2) Aftermarket upgrades. - It is common issue when installing Tech T upgrades for a bolt or Cyclone.
3) Cyclone feed paddles installed incorrectly so it may feed 2 balls at a time. Rare but happens - after feeding cycle ends, paddles should prevent the paintball from falling into the marker. If they are not installed correctly, balls can roll in and out. As a rezult cyclone not fidding or bolt chops paint.
4) Barrel width.
5) Operating pressure - I've seen A5 shooting around 400FPS. And it blew up all the paint other than very hard and cheap one.