yea, i had that happen on my M15. i got like 5 bb's stuck in there because i was trying to reload a damn high cap in the middle of a firefight (i blew all my $ on the gun, so i had nothing for mags). i didnt close the resiviour tab for some reason, and then loaded my M15 upside down, resulting in 15 or so bb's pouring into the magwell, some getting jammed in the same spot yours did. thankfully, they came right out with a shake pointed down.