1851 Navy Cap and Ball Malfunction

Are you sure you are seating the caps all they way onto the nipples?

How stiff is the main spring? Does the hammer pull back too easily?
Remove the grip and check to see that the mainspring is tightened down correctly, and hasn't broken. If it looks okay, it may need replacement.

Could be an obvious answer- dud caps! have you tested one on a nipple with a light hammer I had some damp ones once that kept misfiring

I'm with Rusty bubbles. More than likely the caps are the problem. Try a different brand even. I like RWS best, Remington least.

The cheapest way to find out the problem is throw some parts at it. Like new nipple and new cap. Should be about ten bucks to do that. If it works great if not then look for a new main spring. If you do need a new main spring I came across a company today called Taylor and Sons. They have parts for C&B revolvers. Here is a link:
http://www.taylorsfirearms.com/index.tpl

My eyesight must be going. I could have sworn you asked if CCI caps were more sensible compared to others, and was about to mock you for it. Now I have to mock myself instead. Blindy.

Anyway, I'm not sure about percussion caps, but CCI centerfire primers are known for being the "hardest" on the market. Also, many cap and ball guns are inherently finicky about caps to begin with.

Let the hammer down on the cap easy,then use your thumb to press the cap onto the nipple with the hammer.Be careful and keep it pointed down range while doing so,then you will know the cap is all the way on the nipple.

I had the same problem with my 4 month old uberti '51. IT'S THE MAINSPRING. The newer made 51's have a great feeling light action from the box, but the spring is too light. You should notice that when they do ignite a cap, the blowback through the nipple is sending it into the works, jamming it up. Get a stiffer mainspring, or try one from a Single Action .45 clone if you have one and if they start popping, then ya know for sure.

CH

Also get ya a short piece of wooden dow rod or something similar to set your caps with, it's safer and won't get ya yelled at by the someone next to ya.

CH

The quickest and easiest thing to try is to change to Treso nipples, about $3 apiece at Track of the Wolf, Jedediah Starr, The Possible Shop, etc. They are the top of the line.

If this is a new problem, one that didn't happen when you first got the gun, then the nipples are most likely the cause; the head of the nipples, especially stock Italian ones, will mushroom eventually (dry firing will greatly decrease the time when that happens). When they mushroom it's almost impossible to push the caps on deep enough to contact the ignition material.

Once the nipples are eliminated as a cause the mainspring is almost always the issue; they certainly can get weak. Usually a new replacement is sufficient, and they're not expensive or difficult to replace. I wouldn't waste my time looking for a 'stronger' one (I assume you mean stiffer - stiffness, not strength, is the problem).

I have an older 1851 that would not set off the caps due to a weak mainspring. I beefed it up by adding a piece of a broken mainspring behind it, and now it works fine. Try it and if it works, you'll know it's the mainspring and you can either keep the shim in place or buy a new mainspring.

I've had the same problem with some of my percussion revolvers. What worked for me was to take a few pieces of thick leather and placing it behind the mainspring a little ways above the screw, similar to what Pohill has done with a piece of mainspring. You may have to use one or more pieces of leather and vary the exact location behind the spring but I bet that this will do the trick. Use a sharp knife then to cut the leather even with the sides of the spring so the grips will fit back on. I hope this helps.

There are a lot of things that can cause misfires in a Colt-type percussion revolver other than bad caps or a weak mainspring. One is cylinder end movement (called "end-shake" in a modern revolver), which will allow the cylinder to move forward under the impact of the hammer rather than setting off the cap. Another is failure of the hammer to reach the cap; that can be caused by the cylinder being too far forward and out of reach of the hammer. Another is improper setting of the hammer stop, not allowing the hammer to go forward far enough. Also, the nipples can be too short.

Note that in a properly set up revolver, the hammer will NOT touch the nipples. It will stop just short by about .004-.005", fine to fire a cap but not to batter the nipple if the gun is snapped on an uncapped nipple. That adjustment is made on the frame at the factory, but can be set to be less with a good file. (It can't easily be made greater, though, so don't get file happy.)

Jim

I had that problem with my ROA. The book says to use either #10 or #11 caps. I moved one size larger and it works perfectly. It was a nice, cheap fix.

YMMV,
Fezwig

I had the same problem with two of my C&Bs. A quick way to field-check if the hammer is not reaching the nipple sufficiently to fire the cap is to turn the nipple back out about 1 turn and try it again. (Remove the cap before you screw out the nipple!!) And, no, I have never had any fire blowback problem with the loose nipple; I shot one the rest of the session with the loosened nipple and it did not mis-fire again.

Then, of course, you have to get replacement nipples that will work properly.

colonialrob