I use this hopper on my 98 custom with the Raider M82a1 from opsgear.com and i have had no trouble. For what i do the forty rounds it REALLY holds are plenty. It really does add a sense of reality to the game if you play woodsball and scenario games because the reload is about that of the real firearm. However the lid is a little weak but nothing camo duck tape can't fix. Oh and it needs to be painted OD.
Overall a fine hopper for the patient sniper who makes every shot count.