Thank you Dave for your very kind remarks and I will share some of the information that I sent you regarding your Confederate Whitworth. I have indeed done a very comprehensive examination of 2.75-inch Whitworth bolts that were manufactured by the British, replicated by the Confederates, sold by Bannerman’s and specimens that have been recovered from battlefields. My friends and I have actually made some battlefield recoveries so I know where they were found and I can certify their origin.
Sidney Kerksis and Tom Dickey were perhaps the first to document that the Confederate’s manufactured 2.75-inch Whitworth projectiles for the rifles they imported. John Bartleson further documented this in his epic book and Peter George and Thomas Dickey further acknowledged this in their great works. From my research and observation, the Confederates used two manufacturing methods.
The first method used bar stock to form the projectile. (Reference: Sidney Kerksis and Tom Dickey, Field Artillery Projectiles of Civil War, page 228). They cut bar stock to form a blank and turned the nose and the tail to achieve the correct shape. These projectiles have crude lathe marks on the nose and tail and lathe dimples on the nose and base. The flats were not lathed, but were brought to tolerance by a surface grinder. Don’t ask me how they did this, but you can’t lathe flats. In any event, this was not a cost effective method, must have consumed a lot of machine time and these projectiles are very rare. My research reveals that at least one gun was blown up by “homemade ammunition” at Washington, NC in 1863. ). Dickey and George show this projectile in later editions (Dickey and George Field Artillery Projectiles of the Civil War, page 292 and the revised edition [1993]), but drop the reference to being cut from bar stock.
The second method was far more sophisticated and used a precise casting as a blank. The flats were machined to final tolerances and there was no need to lathe anything. I have been told the Fayetteville Arsenal had this equipment and manufactured these, as confirmed by Jack Wells. Other experts have told me they were also produced at Tredegar and John Bartleson has confirmed that from his research. For a reason unknown to me, most of these projectiles have a lathe dimple on the nose and not on the base, but none have a lathe lug as they weren’t lathed. The dimple was likely to align the surface grinder to finish the flats, but was not to align a lathe. The base on these projectiles is flat and does not have a precise finish, as do British projectiles. The collector’s consensus is that most of the projectiles that are in excellent condition were sold by Bannerman’s after the war. They purchased most of the Union and Confederate surplus ordnance that was sold by the federal government after the war so this makes sense. Confederate bolts have slightly greater windage on the flats for safety purposes (they were not as precise as the British specification), but we can ignore this for now.
So having noted this, the question is where is the proof to back-up these statements? The most compelling evidence is in the weight of the cast iron, per square inch. British iron is so pure it weighs significantly more than Confederate cast iron, except for that produced at Selma using their air furnaces. Wrought iron weighs more than cast iron, but 2.75-inch Whitworth projectiles are not made of wrought iron, so we can skip that technical subject for now.
The bottom line is that typical Confederate cast iron weighs about 0.253351 pounds per square inch. British cast iron since 1759 has weighed about 0.2685743 pounds per square inch. It is very pure, very hard and is very heavy compared to any other service. Thus one pound of British cast iron weighs about 6% more than the average weight of Confederate cast iron (except Selma). While this doesn’t sound like much, it is a significant difference. It means 100 pounds of British cast iron weighs 106 pounds while the same volume of Confederate cast iron weighs 100 pounds.
Thus, if we compute the volume of a 2.75-inch Whitworth bolt and multiply it by the weight of CSA or British cast iron, we can accurately determine the weight of a new, complete solid bolt and identify each by their weight.
To compute an accurate volume, we must select the identical British Whitworth the Confederate’s copied. The British pattern copied by the Confederate’s is shown in Kerksis and Dickey (page 233) at 13.0 pounds; Dickey and George 1980 (page 291) at 12.625 pounds; Dickey and George Revised (1993), page 329 at 12.625 pounds; and Melton and Pawl (page 234) at 12.6875 pounds. Note that none of these authors’s noted a lathe dimple on the nose and all recorded the weight at over 12.5 pounds, closer to 13.0 pounds. This is because all of these specimens are actually British. A Confederate specimen of this pattern cannot weigh over 12.5 pounds.
The only way to accurately determine the volume of any projectile is to place it in water and compute the amount of fluid it displaces. The amount of water displaced in milliliters can be converted to cubic inches of iron. The author methodically conducted these delicate computations using actual specimens.
Without putting everyone to sleep, this writer took the British specimens noted above and compared them to what he determined was a Confederate reproduction. They were very close to being identical, with the Confederate specimen having slightly greater windage for safety purposes.
Liquid displacement testing by the writer revealed the volume of the British 2.75-inch bolt is 49.52 cubic inches. When this is multiplied by the weight of one cubic inch of British cast iron, it reveals a new specimen would weigh 13.3 pounds. The writer believed he had made a miscalculation until he noted General Abbot recorded an identical specimen weight in Siege Artillery in the Campaigns against Richmond, 1866, Plate 6, Figure 75. General Abbot noted his specimen weighed 13.3 pounds. This writer had previously thought this was a typographical error, but it became immediately clear that General Abbot was correct. When noting the British specimens quoted above, all were closer to 13 pounds than the lighter Confederate projectiles the writer has examined. We must note that all projectiles have lost weight due to either burial or oxidation (just exposed to air) because over a period of 140+ years, almost ALL specimens noted to date have lost some of their original weight.
The Confederate reproduction is about 49.2 cubic inches, but when this is multiplied by the weight of one cubic inch of Confederate cast iron (0.253351 lb), it produces a weight of about 12.46 pounds. As simple as this test is, relics that have been buried in fresh water soil or cleaned have often lost 4 to 8% (or more) of their original weight. This makes it extremely difficult to determine the bolt’s original weight, but we can get close enough to make some judgments.
Thus this writer’s conclusion is that any bolt that weighs over 12.5 pounds has to be British and those weighing less than 12.5 pounds are likely Confederate.
Further, any bolt that has a dimple on the nose is a Confederate reproduction. None of the British specimens examined to date had a dimple on the nose and without regard to their condition, have weighed more than 12.5 pounds with most approaching 12.75 pounds or more. To further confuse the issue, some Confederate specimens do not have lathe dimples on the nose, but they all weigh less than 12.5 pounds, suggesting the Confederates either modified the manufacturing process to eliminate the need for a nose dimple or Fayetteville and Tredegar had different manufacturing methods.
The Confederates also produced another bolt of a slightly different pattern and this can be identified by a slightly different nose contour. The writer recovered one at Petersburg, but unfortunately none of the books to date feature a picture of this projectile. This writer has done liquid displacement testing on his specimen and confirmed it is made of very crude Confederate cast iron.
This has been a very long-winded explanation, but this writer is confident of the conclusions reached. If anyone wants to discuss this further, please feel free to contact me at ColJFB@aol.com. Please put Whitworth as the subject so I don’t delete it as spam mail. I’m very sensitive to how controversial this subject is and I don’t want to get in a position where I have to contradict any of the information presented in the past by the true experts in publications, books or on this forum.
I genuinely hope this information will help in the future identification of Confederate manufactured bolts versus those imported from Britain. My experience to date is there are more Confederate specimens in collections than British projectiles. This is a tribute to the ingenuity of the Confederate Ordnance Department that managed to provide ammunition to an Army that was fighting against all odds. I have only found reports reflecting a need for replenishment of expenditures. I’ve not found a single report or read anything that indicated any battle was lost due to a lack of artillery ammunition.
I salute the Confederate Ordnance Department for accomplishing the near impossible.
