Well, a coin edgewise is more aerodynamic than the average rock - people throw playing cards over 100 feet - I've actually seen that done.
What coin would Washington have been throwing? I would guess probably a silver half-crown, which would weigh about two ounces - or about the weight of a golf ball.
Who knows?
But small objects can definitely be thrown 250 feet by a strong teen - especially if the wind is at his back.
After this conversation I have half a notion to bring some dayglo golfballs down to the high school track I normally run on and see how far across the football field I can launch one.
Yes, if they stay EDGEWISE into wind and don’t start flipping, something I’m not seeing someone doing effectively with an overhand throw with enough power to get it 300 feet.
Like I said, a stone I buy, a coin, I’m skeptical.