I've got a pint jar of thermometer mercury. Have always wondered how it would work pouring a hollow arrow shaft full of the stuff.4,000 grains? If the shaft was only 2/3 of the way full, there would be this "slide hammer" effect when the arrow hit resistance [8D].

I'll be interested to see what the trajectory of 2084 grain arrrow looks like. Was kinda surprised how fast you got it going . . . . . would have expected something under 100 fps.