Screw-Breech Percussion Rifle Prototype

In this video and article we’ll examine a somewhat mysterious screw breech percussion rifle – if you, like me ever wondered what a Ferguson with a percussion lock might look like then you’ll find this one fascinating. If you haven’t seen our earlier video on Patrick Ferguson’s 18th century breechloading rifle, check that out!

Right profile of the rifle (Matthew Moss)

This rifle likely dates to the mid-1860s and from some research is believed to be based on a design patented by Lewis Wells Broadwell, an American inventor. Broadwell was granted his first patent in 1861, protecting a sliding breech design for artillery. During the 1860s & 70s Broadwell was employed as the European Sales Agent for the Gatling Gun Company. He held a number of firearms and ordnance related patents, granted between 1861 and 1876. With several relating to artillery carriages, ammunition and magazine systems. His screw breech (US #33876) and a gas check (US #167981) designs for artillery were used by Krupp in some of their guns including the popular 68mm breechloading Mountain Gun.

The rifle with its trigger guard rotated forward and its breech open (Matthew Moss)

Like the earlier Ferguson rifle, which drew heavily on earlier screw breech designs, this rifle has a rotating trigger guard which acts as a lever to unscrew the breech. Rotating the trigger guard drops a rectangular breechblock and opens the action. Unlike the Ferguson the threaded piece does not act as the breech plug itself, instead the separate breech block takes the brunt of the cartridge ignition.

The rifle with its breech open (Matthew Moss)

Broadwell filed the patent believed to correspond to this rifle first in Britain, in May 1863, and subsequently in the US in August 1865 (US #49583). The patent protected the breech action and depicts what Broadwell described as a ‘screwed nut’ below a rectangular vertically sliding breech block. This idea of a sliding breech-block builds on his earlier patent for a sliding cannon breech.

Broadwell’s UK patent, dated 1863 (UK Patent courtesy of Research Press)

In Britain, Broadwell used Richard Brooman, of Robertson, Brooman and Company, as a patent agent. At the time Brooman’s company offered a service by which he acted as the inventor’s deputy and was listed as the patent holder, while the inventor was listed as the ‘communicator’. The service cost the not insignificant sum of £45 (at the time a labourer could earn just 3 shillings 9 pence per week – or 15% of £1 – that’s just under a year’s average wages). This initial sum covered the patent for three years. It is likely Broadwell employed an agent because at the time he was living in St Petersburg in Russia, undertaking negotiations with the Russian Government to establish Gatling Gun production. Brooman was also the editor of The Mechanics’ Magazine, a Victorian science and industry journal.

Broadwell’s slightly different 1865 US patent which is also similar to the rifle we are examining (US Patent Office)

The breech plug has a screw thread with a very wide pitch with flat crests. Broadwell’s US patent describes the breech plug as having a ‘three to six threaded screw’. The breech blog falls enough to allow loading after turning the lever around 200-degrees – ensuring a rapid action. Interestingly the British patent shows the lever not attached to the base of the screw plug but instead shows it at the mid-point of the screw. This may be an error in the drawing. It seems that if the rifle we are examining is a Broadwell prototype it was decided to simplify the action by attaching the lever at the base of the plug.

A close up of the rifle’s trigger guard and screw (Matthew Moss)

This rifle itself, has no markings whatsoever, not even range markings on the rear sight. Typically rifles of this period would at least have a marker’s or patent holder’s mark on the barrel or lock plate. This suggests that the rifle is either unfinished or more likely a prototype which did not require extensive markings.

The rifle’s unmarked rear sight (Matthew Moss)

The breechblock is not blued and is possibly case hardened. Much like the Ferguson, and other earlier screw-breech rifles the trigger guard also acts as the breech lever. Which with a rotation of approximately 200 degrees, descends enough to open the breech and allow access to the chamber. The threaded screw is around 0.5 in (1.2cm) thick and acts on a rectangular breechblock which sits above it. This basic layout matches Broadwell’s 1863 UK patent.

The rifle with its breech partially closes, there is no method of extraction indicating it used a combustible cartridge (Matthew Moss)

The rectangular shape of the breechblock ensures a strong action as it butts up against a pair of narrow shoulders (about 1mm in width) at the rear of the receiver. The rifle has a two band stock and a cleaning/ramrod which indicates a military-style rifle but interestingly, there is no obvious provision for fixing a bayonet.

The rifle is believed to be chambered in a cartridge using a .451 Westley Richards projectile. There is no method for extraction so we can safely assume the rifle used a combustible cartridge, ignited by a percussion cap rather than a self-contained metallic cartridge. Interestingly, the UK patent also suggests the use of a “tubular magazine… formed in the hammer, containing self-acting feeding apparatus for supplying ignition wafers or patches to the nipple.” This is not mentioned in the later US patent and the rifle we’re examining has a conventional capped percussion lock.

A close up of the Note rectangular breech with the action closed (Matthew Moss)

The US patent describes a ‘mechanism to prevent the gun from being fired when the breech is open’, this is formed by a lever which disengages with the trigger when the breech lever is rotated. There is a small leather flange in the base of the stock where the screw ascends and descends, this prevents the ingress of dirt and also acts to keep the screw clean.

Left profile of the rifle (Matthew Moss)

Compared to Patrick Ferguson’s action Broadwell’s design simplifies the breech plug using a simpler to manufacture rectangular breechblock and a thinner screw plug. The use of a self-contained cartridge would have sped up loading but the need to cap the rifle’s nipple was still a limiting factor. The screw breech concept became increasingly obsolete with the introduction of self-contained metallic cartridges with integral primers as well as the introduction of faster actions including bolt actions, falling block actions and toggle-locked lever actions.

Lewis Broadwell was born in Cincinnati, Ohio, on 18th July 1820. He is perhaps best known for his drum magazine design for the Gatling Gun. The Broadwell Drum consisted of a series of single stack, gravity assisted magazine columns arrayed around a central pivot point. These columns held between 15 and 20 rounds depending on calibre and typically there were 16 columns of ammunition. Broadwell patented the drum’s design in December 1870. It was used extensively during the 1870s by a number of militaries around the world, including by the British Army. Broadwell was granted his last patent in 1876 and died, aged 86, in May 1906.

Special thanks to the Hayes collection for letting us take a look at this very interesting rifle. Thanks to David over at the Research Press for help finding the patent and to John Walter for his help finding information on Broadwell himself.


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