Hopefully the posts about 6-pdr field guns has mentioned at least some information which is new. But I must admit the field is “well sown” to start with. One aspect that I like to highlight which is not covered in great detail by other writers is the linkage between the smoothbore 6-pdrs and the rifled guns used in the Civil War. The association map below depicts my thoughts about those links.
So let me explain all the bubbles and arrows.
I discussed the evolution up to the Model 1841 6-pdr in a series of posts – from the iron age, through the Model 1835, through the “light” 6-pdrs, following experiments, and finally the production Model 1841. Concurrent with the establishment of the Model 1841, the Ordnance Department conducted tests with 6-pdrs cast to American forms, but from foreign sources. These foreign gun tests included examples from England, Belgium, and Sweden. Most of those foreign guns were cast iron, but also included two bronze guns from Belgium. (I intend to cover these tests in more detail later when I have a proper photo exhibit of the surviving Belgian bronze guns).
The lessons from those tests spurred additional tests to determine the best metal mix and handling technique for gunmaking. Tests and reports from many ordnance officers from the mid-1840s to the eve of the Civil War lead to specifications for casting iron cannons – both small and large; from Rodmans to Parrotts – for Army contracts. And the most important use of cast iron for field guns came in the form of the barrels for Parrott rifles. Thus the link from the foreign gun tests to the 10-pdr Parrotts.
But the distinguishing feature of those Parrotts – the breech band – had links to Daniel Treadwell’s experiments of the 1840s. After the wrought iron 6-pdr gun tests, Treadwell refined his construction technique with a patent for a “hooped gun.” The discussion of that weapon is best saved for a post on siege and seacoast guns. But the technique resembled that used by Robert P. Parrott on his rifled guns. So much that Treadwell later sued Parrott for patent infringement. While the courts sided with Parrott, the ruling noted a refinement by Treadwell of a long-standing technique. Which in turn Parrott put to practical use.
But Treadwell’s work on wrought iron coincided with similar work by other inventors of the period. One of which was John Griffen, who I mentioned the other day. Griffen’s 6-pdr wrought iron gun became the technical prototype for the more famous 3-inch Ordnance Rifle.
Of course the exterior shape of the Ordnance Rifle came from specifications outlined in the Ordnance Manual published at the start of the Civil War. The Ordnance Rifle shared that exterior form with the Model 1861 6-pdr smoothbore and the James Rifle Type 2 (and I wold also add later production Parrott rifles generally conformed to the ordnance shape, with breech band added of course).
Just before the war the Army ordered some of the old Model 1841 6-pdrs reamed out and rifled with the system developed by Charles T. James. These were the initial lots of the James Type 1 rifles. Additional quantities of the Type 1 were new production straight from the factory. The Type 1 shared the same external form as the original Model 1841 6-pdr. Only in late 1861 did Ames Manufacturing switch over to the ordnance shape for the James Rifle Type 2.
So the three main field rifles in service with the Federals by 1862 – the Parrott, the Ordnance Rifle, and the James – all had connections back to the 6-pdr smoothbore guns. (Although the James soon fell into disfavor.) Further, I would submit these field rifles were the true replacements for the 6-pdr smoothbores, not the oft cited 12-pdr Napoleon guns. But I’ll save that premise for another post.