just did some checking up on some arquebus reference sites and turns out the bullet weights are not as high as i expected nor the bore sizes. they were more like .5 to .75 caliber and the velocity instead of being only 600 ranged from 800 fps for a .75 cal to 1500 fps for a .50 cal.

but i still dont know exact bullet weights but one site mentioned it at 3/4 ounce so if we take the lower velocity of 800*800*330grains/450240 we get an energy of 470 ft lbs but i dont know what cal the 3/4 ounce slug went to.i do know that 50 cal bullets these days usually average about 300 grains for an automatic pistol. so a ball would probably be lighter than a bullet.

so 3/4 of an ounce would probably have been for the .75 caliber.