If i make a loadout with underbarrel explosive launcher and 3 slots of explosives like this
then every time I spawn or resupply explosive item #1 will be absent and lying on the ground
I can pick it up though, except it is rpg. It happens at every resupply which makes it possile to do this:

The standard amount of explosive launcher ammo is 2 and for RPG its 3. But I was greedy so made some tapping at the crate while holding EL and RPG.
x7 looks scary but it lies, I think actual number is 5 for both EL and RPG.