Round balls are impressive harvesting tools. Trivia time, for those you haven't run across the info previously. The 44/45 caliber round ball for revolver and rifles varied from 440." to .454", and weighed 128 to 140 grains. The 36 caliber RB spanned from .350" to .375", and weighed from 70-75 grains.
The selection of these two calibers was not random. They are a derivation of artillery calibration, which used the weight of spheres of pure lead (e.g., a "12-pounder") to gauge their bore diameter. Bores smaller than "1-pounders" were also "gauged" in this way--a 12 gauge shotgun's bore diameter (.729") equals the diameter of 12 RBs that total 1 pound in weight, the 16 gauge is is 16 to the pound, and so on excepting the 410 and 9mm shotshells, which use a decimal/metric diameter for labeling. The 44/45 diameters are roughly "50 gauge", and the 36 calibers are "100 gauge". The 31/32 calibers were derived from RBs of 150/lb; 28 calibers were derived from RBs of 200/lb. Modern handgun and rifle calibers still adhere loosely to these "standards" set up centuries ago using a common element to calibrate dimensions, and seem to cluster closely around them. FWIW.