Made specifically for use in handguns (but still viable in long guns), the PDX1.410 load features three plated Defense Disc projectiles on top of 12 pellets of plated BB shot.
Lester had allegedly put gun powder, BB shot and buck shot from shotgun shells into one with black and red wires that connected to a trigger with a battery port, though there were no batteries inside.
I think the simplest option to get a minnow plug down to the right depth is to use Water Gremlin BB shot or 3/0 shot 12 to 18 inches in front of the lure.