Before saying anything else, I should mention that the markings stamped on CS shells & fuzes are not actually an "Arsenal-mark" (such as the script-A and the 5-point-star on yankee Bormann fuzes). On CS artillery projectiles and fuzes, the letter-mark SEEMS to be an Ordnance Inspector's mark, written in a special code. Meaning, the letter was not an initial of the Inspector's name, nor the facility's name. That being said, it probably represented a major CS arsenal's Chief Inspector.
The fact that in almost all cases only a SINGLE letter was used, rather than the Inspector's personal-name initials, suggest that the single-letter was part of a government-assigned alphabetically coded list, with the single-letter mark representing a particular arsenal or production-facility. The purpose was to enable the CS Ordnance Department to "track" particularly bad-performing (or good-performing) projectiles back to their producer. The idea was probably picked up from the yankees. I've read a yankee artillery officer's report which (in essence) said "The best-performing Bormann fuzes are those which bear the mark of the Frankford Arsenal."
John D. Bartleson Jr. wrote:
>> Mike, thank you for the letter meanings. But where did you get those from?
Emike123 replied:
> In the cases of Atlanta and Selma, projectiles were recovered at the arsenal with those markings. The Samson & Pae attribution is because a shell marked Samson & Pae also had a "Q" stamp on it. The Tredegar association is a bit looser and I'll let Pete tell about that one if he chooses too.
As Tom Dickey wrote in our 1980 book... it is not known for certain that the G mark represents the Selma Arsenal, but a great many artillery projectile products of Selma have it.
Though there are some exceptions, the general rule is "ammo tended to be used mainly in the vicinity of where it was manufactured." In other words, ammo produced in a particular state tended to be used mainly in that state or an adjoining state. For about 25 years, I've been using that rule-of-thumb to deduce the production-origin of various markings. For example, C-marked shells are seldom found outside of Virginia.
In addition, a key clue for the C-mark's origin is the fact that certain types of shells were produced only at Tredegar. An example is the "short" 3.4" and 3.5" Read iron-sabot shells for the "Virginia Reamed-&-Rifled 4-pounder Smoothbore" cannon. The only marking thus far seen on those shells is the C-mark.
Back in the early 1980s, I'd used the "local manufacture, local use" principle to deduce that the D-mark represented an Atlanta facility. Then when the cache of "unfinished" shells was discovered in an old well at the civil war era Atlanta Machine Works property, the only marked projectile in the well had the D-mark.
About the CS Ordnance Department's code-letter-in-alphabetic-order list I mentioned above: Please note that the "most commonly seen" letter marks on CS projectiles are in the FIRST 1/5 of the alphabet. (A, C, D, G, H.) If you include the letters found on Confederate copper timefuze-adapters (which first appear in very-early 1863), the most-commonly-seen letters (A, C, D, F, G, H, I) are in the first 1/4 of the alphabet. I suspect that's not a mere coincidence.
(Yes, I know, the commonly-seen Q on copper timefuzes isn't in the first-1/4 of the alphabet ...but it's almost entirely found on fuzes, not projectiles ...and it is the sole exception to the first-1/4 clustering.
I suspect the missing letters in the first-1/4 (B and E) were assigned to arsenals which got captured early in the war, before the coded-list was fully implemented. (The B and E might have been New Orleans, and Memphis or Nashville).
Important notes:
1- All of the letters past H are very rarely seen ...except for Q when on timefuze-adapters.
2- Nearly all of the "after H" letters have been dug only at Summer-1864-or-later sites.
Here is a list of letters I have observed, and the ordnance type they are MOST OFTEN seen on. I'll include what I think the letter represents, if I think there's enough evidence to support the theory.
A - Broun 3" shells, dug in Richmond/Petersburg area (might be Bellona Arsenal, in Richmond)
C - Long-model Read shells with iron sabot, 30-pdr. Brooke sabots, also some copper timefuzes, Rains Torpedo fuze, Tredegar Arsenal
D - sabot of 10 and 20-pounder Brooke shells, 20-pounder Long-model Read iron-sabot shells, 10"-caliber Columbiad shells, Atlanta Arsenal
F - copper timefuzes, dug in VA and NC (might be a major North Carolina arsenal)
G - field-caliber roundshells and Brooke sabots, 3" Read bolts, 3" Archer bolts, Selma Arsenal
H - 10-pounder Long-model Read shells, 3-inch Read with copper sabot, a Richmond-area facility
I - copper timefuzes (dug in VA)
L - Broun 3" shell sabots (dug in VA)
M - heavy-caliber Brooke Ratchet-Ring sabot (dug in VA)
O - field-caliber Bormann-fuzed roundshells (Alabama and Mississippi sites)
Q - copper timefuzes, a single 10-pounder Long-model Read shell, a Richmond-area facility
R - "Selma-Disc" sabots
S - Brooke Milled-Base bolts (dug in the Richmond/Petersburg area)
T - heavy-caliber roundshells (dug in Columbia SC river-dump, and at NC coastline - Fort Fisher area)
Z - 10-pounder Long-model Read shells (dug in VA sites)
As mentioned, that list is letters on shells & fuzes I've personally examined. As also mentioned, it tells the type of ordnance the mark is MOST OFTEN seen on. I know it's not a complete list. Please feel free to add to it.
There are other marks, which are not letters, but because this post is already extremely long, I'll discuss them in a later post.
Some further notes: As Jack Wells mentioned, the "S&P" (Samson & Pae, a foundry & metal-finishing facility in Richmond VA) mark has been seen with a separately-marked H on a 10-pounder Long-model Read. In addition, the S&P mark with a very-separate Q has been found on another 10-pounder Long-model Read. To me, this is proof that major projectile-producers were "subcontracting" the lathing/metalfinishing work out to local privately-owned metalwork businesses. A foundry can cast far more projectiles in a day than it can do the "finishing" work on ...so the overproduction gets sent out to a subcontractor for "finishing." My point, if it isn't already clear, is that the S&P mark was put onto the shell by Samson & Pae's inspector when the finishing-work was completed there, and the H was applied LATER by the inspector at the larger producer which sent the shells to S&P for finishing-work, as his "mark of acceptance" of S&P's work.
By "finishing," I mean lathing-work, and chiseling off the mold-sprue, casting-burrs & seam-flashing, and reaming out the crude-cast fuzehole and cutting threads into it. We know that Adolphus Rahm's Eagle Machine Works metalfinishing shop in Richmond did such work on many 12-pounder Sideloader Case-Shot and Long-model Reads,, then marked them with the personal initials "AR."
Regards,
Pete
Note: I edited this post in 2015 only to correct a small but important typo error.