Small problem. If you donate a hand gun or rifle without ammunition in serious supply alongside it, said hand gun or rifle is a piece of metal, and wood or plastic these days. One wonders how much ammunition this "virtue signaling" will supply. Not much, I wager.
If they ban anything in 5.56, 5.45, 7.62, 9, 5.7, 12.7, or 4.6 it might free up some ammo.