Easy then, might be able to get them out the BB trap door ? Many seal off the area in the breach where bbs drop i, when doing mods to avoid that.
I read that someone put a dab of hot glue or epoxy in the channel between the BB reservoir and the breech ramp(?), but this involves disassembling the receiver and making sure the glue doesn't interfere with the bolt. Someone else mentioned stuffing a piece of foam earplug in that same BB channel, again making sure it's small enough and in there deep enough to not interfere with bolt. I got in the habit of pushing the bolt slightly forward after pulling it all the way back so that there isn't enough room for the pellet to fall into the BB reservoir channel. Taking off the plastic receiver half is simple if you want to get those stray pellets out. Just remove 6 screws from left side receiver and one screw (the top front screw) on right side receiver. That last screw fastens the right side receiver to the left side receiver, which is why it needs to be removed before you can completely remove the left side receiver. All other screws on right side receiver are there to fasten it to the barrel shroud/pump frame or to the rear stock, so they don't have to be removed. Just don't tighten the screws too much when reassembling since it's easy to crack the plastic (I learned that the hard way on one of my rifles). Finger tight is enough for mine to stay together.
Many seal off the area in the breach where bbs drop i, when doing mods to avoid that.
I read that someone put a dab of hot glue or epoxy in the channel between the BB reservoir and the breech ramp(?), but this involves disassembling the receiver and making sure the glue doesn't interfere with the bolt. Someone else mentioned stuffing a piece of foam earplug in that same BB channel, again making sure it's small enough and in there deep enough to not interfere with bolt.