Underhammeritis - living with the affliction.

In over thirty years of building underhammer guns I have come to notice that there seems to be two kinds of people when it comes to underhammer arms. Those who instantly recognize and embrace the logic and simplicity of the mechanism and those others who view it - may comment that it is interesting - but, ultimately, go back to their “ traditional” flint or conventional caplock guns. But, that’s okay as it takes all kinds to make a horse race.

However, those who do get it really seem to get it. It’s as if a veil has been lifted from their eyes. Some of them that I have known have actually abandoned their other flint and caplock rifles in favor of a fine, custom-made underhammer. They are the ones that I like to say are truly afflicted with “underhammeritis.”

Over the years of writing this blog, you have heard me mention underhammeritis occasionally and some have asked for more information about it and how they might recognize the symptoms. Here is what my research has revealed about this strange malady.

UNDERHAMMERITIS - A fairly common condition in its milder forms that seems to develop among muzzleloading shooters. It is believed by some to be a mental affliction in which the sufferer of said malady is deluded and sincerely believes that there is great merit in simplified percussion firearms actions having as a major element of their design a bottom-mounted, upward-swinging hammer.

There is considerable debate over the causes of this strange condition as some cases seem to start out slowly with only a mild fascination with underhammer arms, which, with more exposure to them, advances in varying degrees of speed.

While in other reported cases, the afflicted seems to be overwhelmed with fascination after just one exposure to a well-designed and crafted underhammer firearm. The final stages of full-blown underhammeritis seem to be complete obsession and there is no known cure. One can only live with the affliction and hope for the best.

In my own experience I am familiar with some extreme cases in which the afflicted shooter completely abandoned - and in one case actually sold – all the other firearms in their collections in favor of their custom-built underhammer rifle.

Granted, that is extreme and it is rare. Nevertheless, it must be realized that such a degree of affliction with underhammeritis is a possibility under certain ideal conditions.

So, what is it about these supposedly unconventional firearms that get those of us who are afflicted so excited? I guess it’s the same appreciation for simplicity that causes us to marvel at Henry’s Model T. So simple and yet so wonderfully functional.

It was the tremendously distracting flash of the typical flinchlock, as seen above, which lead to the original development of the underhammer mechanism in 1750s Europe. Consider that you are supposed to be focusing on sight alignment, trigger squeeze and controlled breathing at this exact moment. Yeah, right. BTW, clicking on any of the photos will enlarge them for closer viewing. Clicking the Back arrow will return you to the text.

Probably more than any other feature, it is that simplicity of design - despite a variety of underhammer mechanisms – that captures our imagination. When you think about it, there has been more diversity of development in underhammer mechanisms than virtually any other muzzleloading firearms design.

All the flint and cap lock mechanisms found on the rifles and smoothbores that are considered to be “traditional” are based on the same design that came over on the boat. Yes, the variations of stock designs may have been inspired on this side of the pond, but the basic sidelock technology is European-based and changed very little in 300 years. The caplock underhammer action, on the other hand, is American-born and bred and is truly as traditionally American as a lever action rifle.

There seems to be some unfounded belief that there is certain nobleness in the complexity of the typical side hammer lock. Many marvel at the mechanical advancements that mark the evolution from the match lock to the finest English caplocks of the late percussion period.

Yes, granted, prior to the introduction of the percussion pill (pill lock) and shortly thereafter, the percussion cap, that complex, antiquated flintlock mechanism was a necessary evil of gun design. But, once Ruggles was granted a patent for his underhammer design in 1826, it’s this scribe’s opinion that the typical gunlock of the time should have become history.

However, that didn't happen and we’re not likely to change the mind of most of those traditionalists so let’s move along.

It’s obvious that one of the major advantages of the underhammer system is its ambidextrous design, being equally well-suited for both left and right-hand shooting. However, there are other advantages that are not immediately apparent to those who have never shot an underhammer or studied the concept.

Our modern traditional rifle was born in the antiquity of arms design and development being the result of an evolutionary process that began with the crossbow. Consider that the typical muzzleloading gun design begins with a long piece of wood into which a channel is cut which will securely hold the barrel. Then more wood is removed to accommodate a complex lockplate and its protuberances. Yet more wood is removed from this frail arrangement to accept a trigger mechanism. And let’s not forget all the screws that hold this Rube Goldberg contraption together.

It can readily be deduced that the result is a stock that is weakest at that most important point of where all the major components intersect. And, all that fuss to do nothing more than simply ignite blackpowder.

Both types of actions do the same thing, that is, ignite blackpowder. Which one makes more sense?

Most underhammer actions, on the other hand, employ some type of “receiver” which acts to contain the hammer and trigger in their proper relation to each other and the nipple and to which the buttstock is mounted. This not only simplifies the design, but the construction, too. In a good underhammer design the result is a rifle with less of a tendency to break at the critical point where all the action takes place.

If one thinks one does not really require a long forearm, then there is considerably less work involved in finishing such a rifle, although, personally, I believe that a forearm of half-stock design is not only functional, but aesthetically pleasing as well.

Looking at the typical flint or caplock action it is immediately apparent that the hammer protrudes significantly above the top of the rifle, as seen above. This is necessary to allow quick and easy cocking of the mechanism. Aesthetically, the hammer or the flintcock is wonderful eye candy that us artistic types are always fiddling with to create something with even greater eye appeal. However, that upward protruding hammer provides Murphy (of Murphy’s Law fame) with untold opportunities to screw up your weekend – and perhaps your life.

Accordingly, if the rifle should by chance fall from your grasp or from leaning against the tree while you answered the call of Nature, Murphy’s Law dictates that it should land on the hammer and either fire the gun or break the hammer, or both.

With the hammer mounted below the barrel, however, the geometry of the stock places the hammer in a very secure and protected location as a rifle almost never would fall and hit the trigger area directly due to the angle of the belly of the buttstock and the length of the barrel. That is, unless, you’ve got some huge hammer that hangs way down below your trigger guard when the hammer is at half cock.

Also consider that the bottom-mounted hammer provides a clear, unobstructed view of both the sights and the target - no hammer protruding into your sight picture. Placing the hammer below the barrel also provides much greater protection to the shooter’s face from cap shrapnel. Be that as it may, many shooters of underhammer guns frequently complain about the cap shrapnel that peppers the wrist and forearm of their left hand – assuming a right-handed shooter – which causes them to flinch. That is so unfortunate because it’s a problem that could have been easily remedied by fitting the rifle with a musket nipple and using musket caps.

I have been a devotee of this simple solution for about 30 years and it still amazes me that shooters will whine back at me that musket caps are so expensive. They’ll buy and burn expensive Swiss powder, but they can’t afford musket caps. Go figure.

Few shooters realize that #11 percussion caps are designed to be frangible. That is, they’re intended to come apart like a grenade when detonated. That feature is most desirable in a revolver where the spent cap can fall free of the revolving cylinder as the hammer is cocked for the next shot. They’re also small and easily fumbled and lost while capping the rifle. (Learn a lesson from military arms - use musket caps.) While essential to the continued functioning of the cap and ball revolver, frangible caps are a pain in the bu… well, actually, they’re a pain in the wrist when spit by most underhammer arms.

Another solution to the cap spitting problem is to design your rifle to utilize a nipple pocket, as seen above, in which the nipple is completely enclosed, or as much so, by the hammer skirt and the nipple pocket. A nipple skirt can also be helpful. The nipple pocket is a feature of more advanced design underhammers of the past, such as the Billinghurst, Churchill and contemporary designs such as the Faeton.

In all fairness, I must say that the Allan Foundry Underhammer Action also provides great protection from cap spitting. BTW, if you take a look at our Underhammer Action Round-up feature of last year, you can read more about the Allan Underhammer Action and why I give it high marks.

If you hunt with an underhammer you will readily recognize that the bottom mounted hammer also provides superior protection over the typical side-hammer percussion when it comes to protecting the percussion cap from inclement weather as well as being inadvertently flicked off the nipple by passing through brush.

And speaking of moving through brush… Of worse consequence is having the typical side-mounted hammer pushed back from the half-cock into the full-cock position as you’re passing through brush. Been there, done that and had the gun go off unexpectedly. Luckily no one was injured, but Murphy had a grand time with me that day.

While I’m sure that other underhammer shooters might be able to add to the list of advantages of the underhammer rifle, those are the basics.

If you’re considering an underhammer just one bit of advice – buy the best quality you can afford. Many shooters begin a new venture looking for a bargain gun just in case they don’t like that type of shooting. However, that is not a fair manner of testing a new concept and creating your opinion. Bargain basement guns generally provide bargain basement results. I have talked with shooters who had at a time shot a low-end underhammer and they were underwhelmed. However, after letting them shoot a well-designed and crafted underhammer, they were truly impressed. One even placed an order for one of my Faeton rifles right there at the range.

By going cheap, you’re only cheating yourself out of what could be a new love affair with underhammers. Or, as some would insist, another outbreak of underhammeritis.

In closing let me remind you that there is no known cure for underhammeritis, there is only treatment which consists of more shooting with your favorite underhammer.

No one said that treatment would be easy, but it’s better than the alternative - that being suffering from underhammeritis and not having an underhammer at all.

Now that would be bad.

Cheers!

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