Carl, I probably know more about these Read shells with 3 flame grooves than you want to know.
1) All were made between Sept. and Nov. 1862 by the Richmond foundry of Snyder & Walker.
2) All iron bodies were cast from the same mold pattern as yours. All have that pronounced lathe 'key' on the ogive.
3) Adding the 3 flame grooves was a stupid mistake. As you can read below, the Richmond Arsenal ordered the three grooves in early August of 1862 for the last of the Tennessee sabots, then corrected the demand about one week later for all field projectiles of 3 inch caliber or less. (Big shells got the 3 grooves for the next few months which might help Jack Bell date some of those in his heavy book.) The orders clearly state that the 3 inch Reads (formally adopted later in August 1862) should have one groove in the sabot as is normally seen in dug examples.
4) Snyder and Walker's error can be forgiven because they were 'newbies.' Although Asa Snyder had produced a lot of canister during 1861, the new partnership began large-scale production of rifled field projectiles in August 1862. They were apparently somewhat 'out of the loop.' The CS Ordnance Bureau had given up on Tredegar as a primary source of field-size projectiles during the previous July. Snyder & Walker completed the earlier Tredegar contract to produce 4,000 of the "Baby Mullanes" 2.25 inch shells for the Mountain Rifle Guns - making the last 2,000 at the same time as they were casting these Reads with 3 grooves.
5) Your Read shell was among 200 or so made in Sept. 1862 with wooden fuze plugs. I can tell because its iron nose was not cut down to seat the flange of a copper fuze plug like those made by Snyder & Walker during Oct. and Nov. of 1862. Identical examples have been dug with the wooden plug that had not been salvaged. A majority of this pattern were equipped with some of the first copper plugs ever put into 3 inch Virginia Reads. It is obvious to me that your shell was salvaged at Chancellorsville or Fredericksburg and then it was threaded and fitted with the copper plug. Further proof is the machining done to thin out the interior of the thick cast brass sabot. This practice became common during the winter of 1863-64, and is not seen on any of the 20 or more Snyder & Walker shells I have photographed. It is well documented that those battlefields were carefully scoured for fired ammunition to reuse. Remember all those 3 inch Dyers. Look at the page from Lee's Thunderbolts I've included below for another salvaged wood-fuze Read with a later copper fuze plug added.
Summary: this is a very cool 3 inch Read from Virginia.
There is more to say about these 'beauties,' but I'll leave it for later.
Woodenhead