First off I want to emphasize that when I say caplock or percussion I am referring to sidelocks, underhammers, mule ears,
and inlines. The only difference in these types of rifles is where the nipple is located in relation to the charge in the
barrel. However the ignition system is the same. The inline rifles that use the shotgun primers would technically fall into
this category as well since they are a form of percussion ignition just using primers instead of caps. I'm not going to get
into any sort of inline vs. traditional debate as both types of rifles have their place and serve their owners well.
In 1807 Rev. Alexander Forsyth invented the percussion ignition system. This was to replace over 300 years of service
with the flintlock ignition. However in the early years they were not as reliable as one might think.
cap is in simple terms a metal "cup" that sits on the nipple. In the bottom of the cup is an impact sensitive chemical
compound. In the early days it was known as fulminate of mercury which Forsyth used. This compound was unreliable, often resulting
in misfires, and extremely corrosive. In the years that have followed the compound has changed several times to it's present
day compound. I do not know exactly what the compound is or I would list it here. I do know however that some are non-corrosive.
(This could vary depending on the brand of cap you buy). In the early days of the percussion era the mountain men didn't
trust them with good reason of them proving unreliable. They also knew that if they ran out of caps in the mountains there
weren't any stores available to them to go and buy more. Also if the caps were lost or contaminated they had no resources
to get more. They relied on the annual rendezvous to buy their supplies and just wouldn't allow themselves to buy this new
rifle with no way to keep supplies for it. Thus these rifles were useless to them. In the early days many of the fur trade
era trappers opted to retain their flintlocks. They trusted them, they knew their guns and what they would do and they just
weren't ready to put their trust into this "new-fangled" invention. Not to mention that if their flint broke they
could find a rock in the mountains that they could put in the jaws and get at least one more shot off.
are new to the sport of muzzleloading most of the time opt for the percussion ignition. There are many reasons for this.
Alot of times it's an extension of season they are looking for. Maybe they are centerfire shooters wanting another season
out in the field. The closest thing they can get to what they currently shoot is the percussion ignition (regardless of style
of rifle). Also for a beginner who may not have someone close by to teach them, a percussion ignition would often be easier
as flintlocks do tend to require a bit more "fussing" with to get optimum performance out of the rifle. For others,
it might mean an added challenge. Either way they choose to go with the percussion system.
Let us look at what
the percussion system does. On the nipple you place your cap. When the hammer falls it ignites the pressure sensitive compound
inside sending a small "flame" through the nipple into the main charge thus igniting the powder.
is one advantage some like about the percussion rifle. It is often chosen as the rifle of choice in wet weather if the option
is there (state regulations like in PA don't allow this however). When you place the cap on the nipple you are (more or less)
sealing off the main charge from getting moisture. When you seat the projectile you are sealing off the muzzle end from getting
moisture. (However an experienced flintlock shooter using a cow's knee or a parka usually does just as well). Several years
ago I recall 2 products on the market that assisted percussion shooters in waterproofing their rifles. Both were called cap
guards. One was a plastic "doughnut" that slipped over the cap and helped seal off the cap. The other one was in
essence a plastic cap shaped "cap" that simply fit over the metal cap also designed for waterproofing. I don't know
if either of these products are still made or not.
Some of the manufacturer's are now allowing the shooter to use
not only standard #11 caps for their rifles, but also musket caps. To use the musket cap you must replace the nipple on your
rifle to accommodate the larger cap. These are beneficial for those who choose to use Pyrodex as it is harder to ignite and
the use of the larger caps would give more "fire" to the powder to set it off. However it is of my opinion that
using an inline, pyrodex and musket caps would be difficult due to the position of the nipple and trying to get the cap on
the nipple. I do not know if there are any companies offering a musket nipple capper. A capper, I have found, to be a must
when using an inline as there simply isn't room to get your fingers and the cap in the small space where the nipple is located.