Congratulations on finding an extremely rare version of Confederate rifled-cannon shell. The after-cleaning photos you posted confirm that it is indeed the super-rare "mid-sleeved" version of a 2.9"/3"-caliber Read Long-Model shell, with pre-rifled brass sabot.
My book about civil war artillery projectiles has a Rarity Rating scale, from 1 to 10, from most-common to most-rare. Your find rates a 9. I've estimated that only about 20 of your shell have ever been found. So, I'm voting Banner for your find.
Yours is the first Mid-Sleeved Read Long-Model shell I've ever seen/heard-of being found in Virginia... which adds to its "specialness." The super-rare variety of shell you dug seems to have been manufactured at a "Deep South" Confederate arsenal, probably in Georgia or Alabama, because all of the (very few) others were found in four Deep South states (GA, AL, MP, and SC). I watched one get dug near the (June 1864) Kennesaw Mountain GA battlefield. I know of a few others being found at Atlanta Campaign sites, and Mississippi, and one from the battle of Blakely AL. Plus one from Sherman's March through SC (early-1865).