Include some shot, or he'll notice the weight difference (or, worst case, stick the wad in his barrel). You could do a 7/8-oz load in a boomer shot cup. Drop the shell in his pouch (instead of in a box that he may not shoot that day) and you'll get to see it go off.I have got to make up some reloads full of confetti and slip them into one of a buddy's ammo boxes
Thanks for the Webb reference. Our new neighbors weren't thinking if having us move, but they'd call the sheriff if a round went off a minute after curfew (10:00).