Milestones in Nineteenth Century Firearms Development, Part Three

The Percussion Caplock

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Two single shot percussion pistols: a Pedersoli .44 ‘Le Page’ reproduction (top) and an original ‘Smith of London’ 17-bore personal protection belt pistol (Circa 1835)


Although the flintlock ignition system was technically advanced for its time, it wasn’t without its shortcomings. Flintlocks require careful setting-up and constant maintenance and adjustment to be reliable. They also have a relatively slow lock time and the flash as the priming charge ignites can forewarn game of the hunter’s presence leading to missed shots.

Fulminate salts, friction-sensitive chemical compounds that explode violently when struck a sharp blow, were first discovered by Edward Charles Howard in 1800 and the first patent for their use in firearm ignition systems was taken out by the Reverend Alexander Forsyth, a Scottish clergyman, in 1807. Forsyth, a keen wildfowler who had long been frustrated by the difficulty of downing flying birds with his flintlock shotgun, invented a mechanism whereby a small container resembling a perfume bottle attached to the side of a gun when rotated discharged a metered quantity of fulminate of mercury into a hollow connected to the gun’s vent. When a small firing pin was hit by the ‘hammer’ (which had replaced the cock) it caused the fulminate crystals to explode, instantaneously firing the gun with neither visible flash nor delay.

Forsyth’s ‘Scent Bottle Lock’ though undoubtedly effective was both expensive to produce and prone to damage and it was soon made obsolete by the invention of the single use percussion cap, a small copper cup containing fulminate. Many flintlocks were converted to percussion quite simply by removing the pan and attaching a bolster to the side of the barrel into which a hollow nipple that acted like an anvil was screwed. The cock that had previously held the flint was replaced with a solid hammer. By the 1830s the percussion lock was in widespread use and the flintlock was obsolete.

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Types of percussion cap – pistol (left) and military rifle (right)

Pistol caps are small and quite fiddly to use particularly if you have large hands and the weather is cold. What they would have been like to use in the heat of battle can only be imagined. For this reason numerous inventors came up with ideas for automatic priming systems, one of the most interesting being the ‘Maynard Tape Primer’ of 1845. Anyone who had a toy cap pistol as a child will have no difficulty in understanding how this worked. A roll of tape with pellets of fulminate incorporated at regular intervals was pushed onto the nipple by a rotating sprocket each time the weapon was cocked. When the hammer fell it exploded the primer and a sharp edge on its base cut off the used piece of tape. Unfortunately Maynard tapes were susceptible to moisture and users got around this simply by using conventional caps on the nipple and abandoning the tape system completely. As larger muskets and rifles use military ‘top hat’ caps with protruding wings at their base, they are much easier to handle so this was not a problem.

The Smith ‘Manstopper’ Percussion Belt Pistol

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A large calibre English boxlock, side hammer, smoothbore pistol typical of those carried for personal protection in the mid-19th century

As this pistol is a genuine antique muzzle loader, it is exempt from the provisions of UK firearms legislation. I was therefore able to buy it legally online without having to obtain prior permission from my local Police Firearms Section. Once I decided to bring it back into occasional use at the range, however, it was necessary to put it ‘on ticket’, that is to have it included on the schedule of ‘firearms possessed’ on my Firearms Certificate.

The pistol, looking very much as it does today, was advertised as ‘needing some attention’ so buying it as a prospective shooter as opposed to a display piece was a bit of a gamble. Fortunately, I have a mate who was just starting up as a gunsmith and ‘Registered Firearms Dealer’ who was keen to do the necessary repairs. He ended up fabricating a complete internal mechanism or ‘tumbler’ for the lock and a new nipple with the result that it now functions perfectly.

This pistol was retailed by Smith of London probably in the mid-1830s but it was made and proofed in Birmingham. This was quite common practice at the time as London-marked firearms commanded higher prices than provincially made ones.

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Retailer’s inscription on the top of the barrel

As you can see, the lock mechanism is far simpler externally than a flintlock. The blued spring clip on the left side of the gun is a belt hook which allowed it to be carried concealed but readily accessible in an emergency. It also has a ‘captive ramrod’ that swivels down for loading the ball and patch before being stowed back under the barrel. Without a ramrod a muzzle-loading firearm is useless, so this was a sensible precaution against loss.

Although this pistol has sights it would only ever have been intended for use at very close range so they are largely redundant. A glance at the business end of the gun should explain why they were referred to as ‘manstoppers’. When it’s a matter of life or death and you only have one shot, you need to make it count and the best way to do this is to hit your attacker very hard with as heavy a ball as is practical.

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The business end of the Smith pistol showing the balls it fires alongside some .44” balls as used in a Colt ‘Army’ revolver for comparison

When a single shot pistol has been fired it effectively reverts to being a club until reloaded so the lion’s head butt cap is a neat touch that would have left an interesting imprint in an assailant’s skull.

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The once gilded lion head butt cap

Using the Smith Pistol

Loading a percussion firearm is exactly the same as for a flintlock except that instead of priming a pan with fine powder all that is necessary is to press a cap firmly onto the nipple and cock the weapon. Before the weapon is loaded, it is always a good idea to snap a couple of caps on the nipple and observe whether a piece of paper, a blade of grass or similar material near the muzzle moves due to the discharge. This ‘capping-off’ as it is known ensures that the nipple and flash channel are not blocked with oil or black powder residues and prevents misfires.

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Here you can see how the captive ramrod is used to push the patched ball down onto the powder in the breech
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With powder and patched ball in the barrel, the pistol is now capped and ready to fire. The hammer is shown at the half cock position

Deciding on what powder charge to use in an antique gun is, forgive the pun, a bit hit and miss as they don’t usually come with instructions. A rule of thumb was to place a ball in the palm of the hand and then pour enough powder on top to cover it – gulp! No fear. Other people say that with a smoothbore you have to use enough powder so that the ball leaves the barrel before it has had time to realise that it isn’t rifled. No; unless the gun arrives cased together with its original powder flask or the manufacturer’s loading instructions on a case label, the only safe way is to start low and gradually increase the charge to a point where the gun is shooting consistently, comfortably and with acceptable accuracy.

After some experimentation, I decided that 40 grains of powder with a thin patch was more than adequate to send the ball into the 25 metre backstop with a satisfying thump. On the odd occasions that I’ve hit the target board there is a noticeable delay between the bang of the explosion and the click as the slow moving ball passes through the plywood and that’s exactly how it should be. It is also noticeable that as the bore fouls after a couple of shots, the recoil becomes noticeably heavier.

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The manstopper pointed safely at the range backstop ready to fire. The targets are 50 metres from the firing point so hitting one with a 5 inch barrel smoothbore would require divine intervention
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A percussion pistol at the moment of discharge is much less spectacular than a flintlock

Accuracy? There isn’t any, but at close quarters as intended this would be a fearsome weapon and any footpad or mugger would have been either exceedingly brave or inordinately foolhardy to have chanced his luck against it. The one practical problem that occurs to me though is in what state of readiness would this pistol have been carried by its original owner? As it doesn’t have a safety catch it could have been carried a) capped with the hammer down which is extremely dangerous; b) capped and at half cock – safer, but guns have been known to go off at half cock or c) uncapped – completely safe but this would make no sense at all considering the difficulty of capping the piece in a hurry. I can only conclude, therefore, that the only practical option would have been to have carried the pistol capped and at half-cock but I wouldn’t fancy doing it myself.


The invention and perfection of the percussion cap was one of the most significant developments in firearms technology. At a stroke the percussion lock made the flintlock, which had reigned supreme as a firearms ignition system for more than two hundred years, obsolete. It provided significantly shorter lock time that to all intents and purposes was instantaneous and at the same time practically removed all prospects of misfires – so no more embarrassing ‘flashes in the pan’.

The invention of the percussion cap also made practical and reliable multi-shot weapons possible and in the next article we will look in detail at what many consider to be Samuel Colt’s finest muzzle-loading revolver, the 1860 ‘Army’ which is a real hoot to shoot.

© Tom Pudding 2019

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