I have too many well-founded doubts to believe they are civil war era.
1- They've been found in only one place, which is NOT a battlefield.
2- None are fired.
3- The one place they've been found (in the river at Milledgeville GA) has also produced several varieites of postwar Ordnance, including postwar projectiles (unfired .45-70 and .30-06 cartridges) and postwar (US Model-1896) artillery friction-primers.
4- Despite claims that they are for a Confederate 2.25"-caliber Breechloading rifled cannon, they are not 2.25"-caliber. I've put a digital caliper on their very-high-raised whitemetal bourrelets, which measure 2.23 to 2.25-inches. Therefore, they would not even slightly engage the rifling in a 2.25"-caliber rifle.
Sidenote to Reason #4:
I've also measured the iron body next to the very-high-raised bourrelets. On the specimens I've checked it is 2.10 to 2.12-inches, which is appropriate for a 2.15 or slightly larger Breechloader -- not a 2.25"-caliber Breechloader.
5- Despite the claim that they are for the "Sumner Oscillating Breechloading Cannon," there seems to be no documentation anywhere which tells the Sumner's caliber.
6- Examination of specimens missing their bourrelets show there are three versions:
One body-groove for a bourrelet.
Two body-grooves.
Square iron body under the bourrelet, and hexagonal iron body under the bourrelet.
That indicates they are Experimental.
7- I've seen an 1880s photograph of a US Artillery officer's personal shell collection, which includes many postwar shells. It shows a projectile which looks EXACTLY like the Milledgeville single-bourrelet bolts, except that it is a much larger caliber.
No, I do not currently have access to that 1880s photo. So let's again dismiss my eyewitness testimony about the photo as being "Hearsay!" (Note the exclamation-point.)
The other six reasons for my serious doubt remain standing -- and they are why the so-called CS 2.25"-caliber Milledgeville bolts do not appear in the D&G-1993 book. Until somebody provides no-doubt-at-all proof which cancels the above six (or seven) reasons, I recommend not paying more than you'd be willing to spend for a postwar, experimental, no-combat-usage projectile. Even if no-doubt proof someday surfaces, only the word "postwar" would be subtracted from that descriptive phrase.
