After reading CBG's response, it triggered by memory about the octagon shaped barrel. In Celeste and David Topper's book "Civil War Relics from South Carolina" he shows two SC made rifles with that barrel. In reviewing his book, the first one was made by a Jos. Beaudrot of Charleston. He didn't indicate the caliber, but underneath it he presented a picture of two Whitworth bullets. Interesting to note is he called them .52 caliber. He also presented one of .45 caliber made by Happoldt of Charleston.
There is some potential for confusion here with respect to bore vs calibre, differences in standards for America vs England and also because of the hexagonal rifling for the Whitworth. English bore numbers always referred to the bore diameter not the groove diameter and a 51 bore equated to .450 calibre. The Whitworth was .451 calibre, with the barrels actually being
proofed as 52 bore and carrying this proof mark. For the Whitworth, if you measure from the corners of the hexagon, it would actually be 42 bore (equating to .480 calibre).
Although I don’t think this is a Whitworth bullet, there are a few other things to note, plus a little more history. People talk of “the Whitworth Rifle” as if it were a single item but it came in multiple variants, including three different barrel lengths (but all with the 1 in 20 hexagonal twist at .451 calibre). The records show that 13,400 were made between 1857-1865. From the known Confederate ordnance documents, only 250 of these rifles were purchased by the Confederate Government and a further twenty or thirty were run through the blockade to the Confederacy in 1862.
For the Confederates, the main issue was the price, which they found shockingly high. A standard Whitworth, cased with accessories including telescopic sight and 1,000 rounds of Whitworth-produced ammunition was over $1,000 and even the bare rifle itself was almost $100 (versus an Enfield at between $12 to $25). For that reason, many of (most of?) the rifles they bought were “2nd quality” and marked as such.
As well as having a hexagonal profile matched to the rifling, original Whitworth bullets were elongated, made from ‘hard’ lead (lead/tin alloy), pressed rather than cast… and expensive. Whitworth rifles were supplied with a hexagon bullet mould which (in contrast to the rifles themselves) was of notoriously poor quality, impractical in use and came with the cautionary note: “Projectiles cast from the mould are not to be relied upon for accurate shooting, unless they are passed through a die-press.”
However, the Whitworth was perfectly happy firing cylindrical bullets as long as they were made of ‘soft’ lead (pure, unalloyed) such that they could expand to bite into the rifling. You could make those yourself or buy them cheaply from Eley, Ludlow or any of the usual makers. Each Whitworth rifle also came with a mould to cast elongated cylindrical bullets and the rifle’s leaf sight was graduated with an ‘H’ on one side and a ‘C’ on the other to accommodate the use of either hexagonal or cylindrical bullets. Cylindrical bullets left the barrel with pretty much the same hexagonal profile as those that had been made as hexagonal to begin with. The majority of shooting seems to have been with cylindrical bullets and certainly that was the preference for Confederate use.
In addition to the .451 calibre rifles, smaller numbers were produced in at least two other calibres with the same twisted hexagonal rifling to the barrel. There was a larger .568 calibre and also a smaller .300 calibre. These were Whitworth Military “Match” rifles for competitive target shooting, not designed for combat. You couldn’t fit a bayonet to them (an optional extra on the .451) and they had delicate sights which were unsuitable for military field use. Whitworth rifles are rare enough but the smaller .300 calibre is
extremely rare and I have only seen reference to two surviving documented examples.
