Pinfire Shotgun

Remembrance of Things Past

The pinfire shotgun has always fascinated me. Most of us think sporting shotguns evolved in a logical progression from muzzleloading to breechloading designs. There were flintlocks, then there were caplocks, then there were centerfire shotshells.

In actuality there were many ignition systems besides those. Some failed, while some merely bridged the gap between others.

There were, for instance, pill, pellet, tube, and roller locks---all of which were percussion systems---before caplocks finally hit the gunning scene. Similarly, there were innumerable ignition systems tried for breechloading arms before the centerfire cartridge evolved for sporting shotguns.

One of the more interesting of these vareties is the pinfire shotgun. Although pinfires were a stopgap system that only lasted 20 years or so, they were the direct ancestor of centerfire systems. Indeed, the centerfire (or the more descriptive “central fire,” as the British put it) shell is nothing more than an innovation of the pinfire shotgun system, rather than all new state of the art.

The pinfire shotgun system is both simple and complex at the same time. A paper shell was attached to a brass headplate. Mounted to the inside of the brass was a percussion cap. Extending from that cap, up through a hole in the brass, was a metal pin. Pins usually were brass, but iron was used too.

If you examine a pinfire shotgun, such as my A. Agnew 14 gauge, which dates from about the American Civil War period, you’ll see two small holes at the top of the barrels where they meet the water table. Actually, they’re notches, but they look like holes when the gun is closed. The pin from the cartridge extended up through those holes. When you pull the trigger, the hammer drops onto the pin, driving it into the cap, which explodes to ignite the powder.

A caplock, understand, works because the hammer bangs the cap again an anvil (the nipple), causing it to explode. If you just moved a percussion cap to the center of the shell and struck it, it might, or might not, explode. Think about that for a moment. What if you shift the anvil into the cap itself? You wouldn’t have to puncture the cap with the pin. Instead, the mere act of sharply banging the cap with a pointed object would cause it to explode every time.

And that’s exactly what a modern primer is---nothing more nor less than a percussion cap with an anvil built into it. We hit it with a striker or firing pin and it explodes. This is, as noted, only a refinement of the pinfire shotgun system, not a totally new development.

Hard as it is to believe now, breechfire shotguns were not welcomed with open arms by gunners. Even the reliable and quick-to-load pinfire shotgun was viewed with skepticism until very late in the game.

Like many advances in nineteenth century shotgunning, pinfires were invented in France, where they were more a curiosity than a serious shooting system. Once the British gun trade discovered them, however, the full art of the world’s best gunmakers was brought to bear.

One result was that shotguns returned to having the grace and style they’d lost when the shift was made from flint to percussion. Pinfires have the long, smooth-flowing lines of a sidelock flinter, and the locks, themselves, are thinned down and extended. Caplocks, most of which are boxlock designs, tended to have short, blocky locks, most evident in their clumsy-appearing hammers.

How well do pinfires shoot? Unfortunately, I haven’t gotten to fire the Agnew. While pinfire shells, and the special equipment used to reload them, are occasionally seen at gun shows and on ebay, I haven’t found any in the 14 gauge size I need.

If you hear of any, let me know. The Agnew is the only shotgun I own that I haven’t shot, and I’d like to change that.