As strange as it may seem, the underhammer principle has 18th century Germanic roots and was developed to improve flintlock ignition! At first thought that may seem rather ridiculous as anyone who has ever studied or fired a flintlock knows that the priming powder would simply fall out of a pan and frizzen mounted on the bottom of a rifle. And it is just that fact that resulted in instantaneous ignition in the new mechanism. When you think about it, it makes perfect sense…
At the moment that a bottom-mounted frizzen is opened by the upward swinging flint cock, the priming powder falls freely and becomes dispersed into a sort of little cloud in the immediate proximity of the meeting of flint and frizzen – and it is just at that exact moment that it is showered with sparks from the flint. The resulting upward flash is just fractions of an inch from the flashhole and ignition is virtually instantaneous – at least in comparison to the traditional method. Unfortunately, anything that deviated from the norm at that time in history was usually considered with suspicion as being inspired by the devil and best left alone. However, once percussion caps made the scene all that seemed to change.
"Traditional" sidelocks are rather complex mechanisms and require considerable skill in design and building. In fact, most locks were trade items imported from Europe as few American gunsmiths had the skill or machinery to manufacture gun locks. This set the stage for the development of the percussion underhammer system.
In the early 1820s Reverend Forsyth's percussion cap made its debut on this side of the pond and underhammer development in the newly formed united States of America began with the issuing of the very first firearms patent for a production gun to Fordyce Ruggles on November 24, 1826. Due to a fire some patent files were destroyed. However there is good evidence and it is believed and accepted that the patent was for his underhammer pistol design which became the basis of so many copy cat designs of the following two decades. Unfortunately it was the copycats who gained greater fame than did Ruggles. But it all began with Fordyce Ruggles - the father of the American underhammer. Fordyce and his brother, Adin, set up shop in Hardwick, Massachusetts in December of 1825 and the rest, as they say, is history.
Interestingly, and unfortunately, there are many otherwise knowledgeable gun folks who seem to have a certain prejudice toward underhammer arms in general. Many claim that they're just not "traditional" like flintlocks and caplock guns. Well, it should be abundantly clear that underhammers are as traditionally American as is the lever action repeating rifle. The flintlock technology referenced as being "traditional" is not American-born and bred like Ruggles' underhammer design. Those inferior antiquated designs came over on the boat! What Ruggles offered was something completely unique and new.
Our mate from down under, Terry, has written a nice piece about the Ruggles pistol which you may wish to check out here: http://underhammers.blogspot.com/2010/11/father-of-american-underhammer-system.html .
During that westward expansion there was a plethora of underhammer makers producing both singleshot and even a few repeating underhammer pistols throughout the settled East.
While underhammer pistols seem to have dominated the trade, there were a number of makers of rifles as well. Some displaying great care and skill in workmanship as seen in the example of one of Billinghurst's fine rifles, below. Many of these higher grade arms were very accurate target rifles and some were even used as sniper rifles in the War Between the States.
While many underhammers were simple, both in function and adornment, some designs were mechanically quite unique while others were downright gaudy. The one below displays both characteristics and is from an unknown maker. An interesting feature of this rifle is that the flip side bears decoration that is an exact mirror image of this side - including the patchbox lid!
Meanwhile, European gunsmiths were likewise discovering the virtues of the simple, rugged, and reliable underhammer action and also contributed much to its development.
Interestingly, virtually anyone who was anyone in the arms industry prior to 1860 seemed to have either an open or closet fascination with the simplicity and innate ruggedness of the underhammer mechanism. In fact, Jonathon Browning’s first commercial firearm was an underhammer!
Contrary to what many assume, not all underhammers were simple mechanisms. In fact, some designs, such as the Demeritt, were so complex and/or frail that one has to wonder, "What was he thinking?!"
Now I know that some of you are still waiting to hear about Hopkins & Allen and how they figure into all of this. During the 1950s and ‘60s interest in muzzleloading arms really picked up. Enter George Numrich of Numrich Arms. George had an idea that there would be a market for a simple, inexpensive muzzleloading rifle – and indeed there was. After studying some of the designs of the early underhammer makers, he decided to offer a version which combined features of some of the better aspects of those early designs along with a few twists of his own.
Having acquired the remaining assets of the old Hopkins & Allen manufacturing business - including the name - he graced his new offering with the old name and has confused shooters ever since.
For many years Numrich Arms was the only (visible) maker offering an underhammer rifle – and, yes, a pistol, too – and because so little was known of underhammers outside of collectors circles it was generally assumed that Hopkins & Allen, or Numrich Arms, invented them.
Despite the unintentional confusion generated by his application of the old H&A moniker to his own underhammer design, George made a tremendous contribution to the muzzleloading revival by providing a reasonably-priced, reasonably accurate, muzzleloading rifle which served to introduce tens of thousands of shooters to our sport.
His clever lockwork design was also one of the very few that incorporated a half-cock notch for safely carrying the piece afield. By and large, most underhammer designs of the past did not incorporate a safety notch in the hammer. Boy, would today's attorneys have a field day with that one, or what?
So now you have the story – or at least another page of it. The rest, as they say, is history. No pun intended.
For more underhammer history and trivia that is sure to make you the life of any party, you may wish to track down Herschel C. Logan's great book, THE PICTORIAL HISTORY OF THE UNDERHAMMER GUN. It has been out of print for decades, but a good book locator may be able to track down a copy or you can try Amazon: www.amazon.com.
And for those of you who really need all the details on early underhammers, you will be pleased to learn of a new book by Nicholas Chandler, EARLY AMERICAN UNDERHAMMER FIREARMS. You can learn more about Nick's fine book here: http://underhammers.blogspot.com/2010/12/early-american-underhammer-firearms.html