Here’s a handy invention by Forum member RayJay from Georgia. It’s a simple wire clip that will hold the lid of your plastic ammo box fully open during use. RayJay explains: “Everybody probably uses the cheap plastic cartridge cases. The only problem I have with them is the lid is always in the way and sometimes when trying to open the lid farther the cartridge box tips and you can dump out the cases. I did some cogitating and came up with these .061″ music wire clips. They work great and the unexpected benefit is that the cases are more stable while sitting at the bench.”

RayJay adds: “The round wire is ideal because it still allows a cartridge to fit in the hole where the clip is placed. Now all I need to do is make another 15 or 20 so I can have one in every case I own.”

Another Answer — Buy Better Ammo Boxes with Mechanical Hinges
Many common types of ammo boxes do have this annoying issue of the lids resisting opening and not staying fully open. However, some of the better boxes from Plano and MTM now have a proper hinge, so that the lid lies flat. Even the basic MTM P50 boxes now have a Mechanical Hinge so the lid opens all the way and lies flat when open (see video at 00:48):