© C.V. Clark 2004

(Revised February 2008)

As an addition to 'The Wolverhampton Gunlock Makers', this section is included to give a brief description of the general principles on which many gunlocks work. It is not intended as either an in-depth account of all the many variations of gunlocks produced over the centuries or an instruction manual of how to make or repair gunlocks.

Notes on Guns & Gunlocks

Although the earliest gunlocks are often thought of as being matchlocks, this is to some extent incorrect. The matchlock, consisting of an 'S' shaped lever (the serpentine) with jaws holding a smouldering piece of cord (the match), required no conversion of potential energy to kinetic energy to produce a source of ignition. The serpentine was no more than a means of moving the lit match into contact with the priming powder, the flame of which, when ignited, was transmitted via a small hole in the breech of the gun barrel (the touchhole) to set off the main charge therein.

The first true gunlock was the wheellock. Using the potential energy of a compressed mainspring, the wheellock had a rotating serrated hardened steel wheel to produce a shower of sparks from a piece of pyrites. The sparks then served the same function as the match of the matchlock. However, because even the simplest wheellock required considerable skill to make, it was expensive and was soon replaced by the flintlock.

The flintlock was used and developed over several centuries, its basic mechanical arrangement becoming somewhat standardised and, in part, forming the basis of almost all later types of gunlock. It works by a powerful mainspring exerting force upon a pivoted internal component (the tumbler) to give a partial rotation to the cock, which holds a piece of shaped flint. The flint, forcefully hitting and sliding against a mechanically positioned piece of hardened steel (the frizzen), produces a shower of sparks on to the priming powder. 

In the next era of gun development - the percussion era - the cock of the flintlock became the hammer used to explode a percussion-sensitive chemical compound. The resultant explosion being transmitted directly to the main charge contained in the gun barrel. Obviously this system did away with the priming pan and frizzen, so improving the speed and reliability of ignition.

The gunlocks described above were all used on guns which were loaded with powder and shot via the muzzle, hence the general term 'muzzle-loading' being used to describe them. It was only a matter of time and considerable experimentation before the idea of having a self-contained, self-priming cartridge became a practical reality. Then, the hammer of the percussion lock acted upon a steel rod (the firing-pin), which in turn exploded the priming compound contained within the base of a cartridge (also containing the main charge and projectile) loaded directly into the breech of the gun. The earlier forms of breech loading guns often used the pin-fire cartridge; this cartridge having its own self-contained firing-pin. The more practical system had firing-pins which were part of the gun's mechanism, acting upon primers situated in either the centre of the cartridge base (centre-fire) or the rim of the cartridge base (rim-fire). Both were so successful they became the cartridges as used today.

The advent of the breech-loader saw two main and distinctly different types of gun action develop. One branch of development produced the drop-down or break action, where the barrel opens and closes upon a hinge; it was to become popular on sporting shotguns and rifles, often of the double-barrelled type. The other branch of development led to the bolt-action, where the action (sometimes known as the receiver) and barrel are fixed in line, the breech being opened and closed by a block - also containing the linear arrangement of the firing mechanism - and resembling a common door bolt; initially it became the preferred action for predominantly military rifles.

The development of the drop-down/break-action precipitated the development of the hammerless automatic gunlock. Although the mechanical arrangement was essentially the same as in the earlier gunlocks, the fundamental differences allowed for the tumbler to act internally as the hammer and the gunlock to be cocked by an internal lever operated by the opening or closing of the gun.

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