A subject near and dear to my heart; let's us consider the toy cannon. On the whole, nothing is seemingly as symbolic of our miniature armies as that. Yes, you may have your riflemen, your snipers and the random fellow heaving a grenade. But nothing says miniature warfare quite like the toy cannon.
At the turn of the last century, the William Britain Company in England excelled at the production of functional cannons. Not that they fired real rounds; they used springs to achieve the desired effect. While the Britain's cannons were not the first, they certainly represented the ultimate manifestation of 1/32 scale hostility.
Most of these early cannons used a firing mechanism that has become somewhat rare these days. It consisted of a lever that slid through the breech of the weapon, thus hurling the projectile towards their 54mm sized opponents. The legendary 4.7" naval cannon from that early epoch was stated, in the words of H.G. Wells, to be capable of throwing a round nine yards. Keep in mind that most English houses of that period were not that big, and one wonders just how many dings and dents the average parent found in the paint, plaster and wallpaper. Warfare probably migrated to the garden for that very reason.
The sprung lever may have been an early firing system, but it wasn't alone, and soon other systems would evolve as well.
In other words, there was more than one way to skin the proverbial cat, or at least to lob miniature rounds.
The primary miniature firing mechanisms can be broken down thusly -
Levers, hammers, pushers and pullers.
The hammer was a logical development of the lever. It works very much in the same manner as a hammer on a rifle or handgun; pressing on a trigger causes the hammer to strike the breech of the cannon with enough force to propel the round. This is the path that the Britain's 4.7" naval gun in later development. While the hammer did not supplant the lever in some guns (the smaller guns kept the levers, as did some examples made by the likes of Tootsietoy and a sole example from Barclay in the United States), it certainly did become more common on larger pieces.
The pusher is different in that the prime mover is almost always found in the barrel of the weapon. That prime mover is almost always a coiled spring. The pusher relies on a piston with a shaft that feeds through the spring and out the breech. Simply pulling on this shaft and releasing it fired the round; there was rarely a trigger at all. The vast majority of the "dime store" cannons used this method, with notable examples in the Little collection being manufactured by Barclay and the French firm of Simon et Rivollet.
The puller is a rarer beast, seldom seen afield. In this instance, the piston is pulled, either by spring or elastic band, through the barrel; it is almost a combination cannon and slingshot. In the 1950's and 60's, a number of inexpensive plastic toy cannons used this method, almost always using elastic. On the upside, they were easier to repair. The downside is that elastic will eventually break down and snap, usually when the weapon is armed for firing.
The big question that seems to remain is which method works best? Do we test, do we quantify? Should we even dare?