Musket Balls

[macman]

These two musket balls are said to have been collected from the site of the battle of Williamsburg, May 5, 1862. Could anyone shed any light on these two rounds.The larger of the two is approx 5/8"/16mm in diameter and weighs 1oz, the second is roughly the same size and weighs in around 0.9oz. I am guessing that they are both the same caliber despite the weight difference.

[PCGeorge]

Contrary to what most of us thought when we started collecting or digging civil war ammunition, not all "round" balls are bullets (or cannonballs).

1- Some types of civil war artillery shells (called Case-Shot ammunition) contained antipersonnel balls/slugs ...which can be very difficult to distinguish from musketballs. The general rule-of-thumb is that musketballs were carefully manufactured as a "Perfect Sphere" (like, say, a glass marble, or a ball-bearing) ...and case-shot balls were usually NOT a Perfect Sphere.

2- Extra-precise size measuring is also very important for distinguishing between musketballs and case-shot balls (and for bullet Identification in general). That is why most bullet collectors buy a set of digital calipers. The rule is, if the object's precisely-measured diameter is not a correct fit for any civil war firearm, it is not a civil war bullet.

So... applying rules 1 and 2 to the specimens you posted:
1- The ball in your first photo does not appear to be a Perfect Sphere.
2- You say they both measure approximately 5/8"/16mm (.625-to.64") in diameter. That size is not a correct fit for a civil war musket. Therefore, it's most likely that your specimens are lead case-shot balls from exploded cannonshells.

Sidenote:
Although your post did not ask about cannonballs, the following info is important enough to include in my reply. Every actual cannonball was carefully manufactured to be a Perfect Sphere ...not out-of-round (for example, a pea or a tangerine). The reason for the Perfect Sphere shape is that if a cannonball is lumpy/bumpy/out-of-round, it is very likely to jam in the cannon's bore during firing -- which can cause the cannon to burst -- and that is very bad news for the cannon's crew. So, part of a civil war Ordnance Inspector's job was to carefully check every cannonball to be sure it was a Perfect Sphere. Ebay auctions have lots of "round-ish" iron balls which are not cannonballs, but in actuality are rock-crusher balls from the Stonemilling Industry. Also, remember Rule #2 ...even when a ball is a Perfect Sphere, if its precisely-measured diameter does not match up with any of the various sizes of civil war roundball ammunition, it is NOT a cannonball (or in your case, a musketball).

Regards,
Pete [P.C. George]