Factual error: The semi-auto handgun is not a real Bergmann 1911. It is a Walther P-38 that was modified to look like a 1911 Bergmann, but when Michael shows it, he puts the magazine in the grip rather than in front of the trigger, as a Bergmann would require.
Factual error: The scene where Jon Wayne's Son is shooting the deer at 600 yards, he swings his rifle about 20-25 inches in about 2 seconds - by my calculations the deer must have been travelling around 250 mph.
Factual error: The motorcycle that Michael McCandles rides is far too modern for the era of the film. It has twin coiled rear suspension and offroad tyres on it from a more modern 60/70s era.
Answer: A U.S. bill weighs roughly 1 gram so that about 454 bills (regardless of denomination) weighs 1 pound. It takes 50,000 $20 bills to equal $1M. Which is about 110 pounds. Of course this is freshly minted weight, so any debris and anything used to secure the bills would increase that weight).
Bishop73