Caps not firing on first hammer blow.

I am havng an issue with my smooth rifle, the caps (CCI #11 magnum's) arent going off on the first blow from the hammer, most of the time, what I mean is maybe half the time it will go off first time and the other it takes two tries.

What can cause such a problem, I have ead that it may be due to a mushroomed nipple, but I dont think that is the issue as I have tried turning it a little in my drill press with a file at least a half dozen times, the cap fits easily on and must be pinched for it to stay on.

Anyway today I am going to make a new tumbler that will allow me to get more performance out of my mainspring, hopefully a a more powerful blow from the hammer will increase reliability.

Does the main spring feel weak to you when you cock the gun?

A weak main spring could cause this kind of problem, another idea could be the inside of the lock is over torqued and binds as the action is worked.

Give the lock a good oiling to free up any resistance internally.

This is nearly always a case of the caps not fitting all the way onto the nipple. The first hammer fall drives the capp onto the nipple and the second hammer fall sets it off.

Solution is to get a nipple with a smaller neck or to put your nipple into and electric drill on the threaded end and spin it with a file on the nipple neck until you get the diameter to where the cap will go all the way onto the nipple.

Something could be binding in the lock mortis not letting the hammer fall all the way. Could be a shorter nipple, just some ideas! Good luck.

Try a different nipple. It's a cheap way to fix the problem and if it doesn't, at least you've eliminated one source of the problem.

What Marmot said.

Put some lipstick, or marking dye on the top edge of the nipple. Then, lower the hammer down on the bare, NEW nipple. Now, cock the hammer back to full cock, and upend the guns so you can look inside the skirt to see the face of the hammer? If you don't see a complete Ring of lipstick, or marking dye transferred to the face of the hammer, the hammer is not striking the nipple squarely. Worn nipples will have one side or the other peened down, by the hammer, and will conform to the angle of the face of the hammer. However, the percussion cap is still as Square as it came out of the punch press, and now has to conform its shape to the angle of the face of the nipple.

That is the problem.

To solve it, get a small grinding bit sold in hardware stores for Dremel Tools. If you don't have a Dremel tool, but have a electric hand drill, you are in business. Chuck the small grinder into the drill and turn it on medium speed, until you learn what you have to do to control the drill while its grinding off the surface of the hammer face. Grind off the area where the dye appear. Those are the high spots.

Keep testing the hammer with more dye on the nipple, to see how you are doing. The goal is to remove the high spots so that the face of the hammer hits the nipple( a New one please!) squarely and transfers dye from the full circumference of the top of the nipple. You should have a full ring of dye on that nipple when you finish, of even width all the way around the circle.

When the hammer is hitting the nipple square, it should have no problem igniting it every time you pull the trigger on a fresh cap. Do invest in some spare nipples. They cost very little, and spares are nice to have when you need them.

I always put a New nipple on my rifle before going deer hunting. I test the new nipple- some are made too tall or too short for your gun- so always measure them. In fact, when I go to buy new nipples, I take one of my older ones with me, to use to measure to make sure they are the same length( height), and thread size.

Don't forget to compare the threaded portions, too. Some companies made nipples with longer threaded shanks. If the nipple screws down too far into the drum, or bolster, you can actually impede the firing of the gun. There is too little room under the orifice of the nipple for the fire to get on by the outer edge of the nipple, to go down the flash channel to the powder charge. Hang fires are the most common symptom, but some guns actually experience misfires, too.

If the main spring was weak the caps would not go off the second time although a stronger mainspring could be powerful enough to fully seat the cap and explode it. Get a nipple that the caps fit properly. Fastest, easiest solution. If that doesn't work then worry about a more powerful main spring.

There are a number of things that can cause this problem. Let's start with the simplest fix and go from there. First, try some new caps to see if they work. You may have old caps or they may have gotten wet at some time. Next, are the caps fitting properly on the nipple? Then, take a look at your hammer to see if there is any crud built up in there. Use a small screwdriver to carefully scrape aropund inside the nose of the hammer to see if it has any crud build up. Also look for spent caps that may be stuck in there. If the hammer nose is clean, take a look to be sure it is striking the nipple squarely. Then examine your nipple. Is it mushroomed and is the top square. If it has been beaten so that it is not square, it will not fire caps reliably. Next look at your mainspring to see if it is getting weak. It has to be one of these things. If you have good caps that are properly fitted to the nipple, a strong mainspring, a clean properly oriented hammer and a good nipple, it is going to go bang first time.

I have had the same type of misfire problem and did try all the sound advice given above. I ended up removing my caplock to inspect it. My problem turned out to be a couple of lock screws that were a little loose, just a quarter turn. My rifle worked perfectly after I tightened the screws and reinstalled the lock and barrel. Good luck.

I have one that does the same thing. If I just normaly put the cap on it won't go off the first time, but always second pull, if I put it on and push it down real hard it will always go off first pull! It's a new nipple, I'll have to take a file to it slightly to make the cap seat better.

As some of these folks said the most likely thing is a misshapen nipple. A little hand filing will probably fix it.

Thanks for the advice, I filed the nipple somemore, and I think I have the problem almost fixed. I will try what paul said about putting the marking dye on the nipple to see how the hammer strikes it.
Its a "custom" gun so buying a nipple isnt an option, I would have to turn a new one on my drill press.

May want to check with the builder about the nipple. They have to get their parts from somewhere. Few, if any, make thier own nipples. Last resort, drill out and retap the threads for a common, availible nipple. Just a thought :v

I seriously doubt that the nipple is " custom" made. Take it to the hardware store, near you, and ask them to use a thread gauge to tell you the thread count. They will have both Metric, and USA thead gauges. Then measure the diameter of the threaded shank. The most common USA nipple will be threaded 1/4-28, meaning that the shank is 1/4" in diameter, and there are 28 threads to the inch.


If you don't already have a nipple wrench, you need one. Stop everything and order a nipple wrench. They generally come in two sizes- a small diameter wrench used to remove small nipples from revolver cylinders, and a larger wrench used to remove or place nipples in rifles, and shotguns. But the larger wrench. I have one made by T/C, that has a nipple wire, or " prick " attached to the underside of the brass cap, to use to clear the hole in the nipple of your gun when it gets clogged. That wrench actually has gotten more use lending it to other club members, than on my shotgun, which is now the only percussion gun I own. :thumbsup:

I have seen nipples that had a hole that was too small in the top of them. There should be a chamfer in the top, you can open it up with a small center drill(by hand). It sounds like that with your abilities that you will whip this. Standard threads are 1/4 28. But you can get 5/16 24 or metric sizes.

Paul

Paul, the nipple is custom made, by me for this gun. I needed an extra long nipple, it is 7/8" OA with 7 x 1mm threads, I turned it on my drill press which is hand powered, pathan style.

I actually built the whole gun by hand using basic hand tools, most of the holes are actually drilled with an old fashioned eggbeater drill, but I had to resort to using my hand powered drill press for the nipple because the first two I hand filed didnt come out so good.

I got it working good today, I filed a 45 degree angle chamfer around the top of the nipple, and the caps now seat and go off first strike.
Thanks everyone for the help.

marmotslayer said:

This is nearly always a case of the caps not fitting all the way onto the nipple. The first hammer fall drives the capp onto the nipple and the second hammer fall sets it off.

Solution is to get a nipple with a smaller neck or to put your nipple into and electric drill on the threaded end and spin it with a file on the nipple neck until you get the diameter to where the cap will go all the way onto the nipple.

Click to expand...

Done it, works like a charm, never had a misfire after that. I used Lansky knife sharpener stones and went slow, checked often until I got a perfect fit and reliable ignition every time. I think it took a little over an hour of time to fix it.

This is a great site! :hatsoff: Was having same problem with my GPR. Hammer assembly needs to move slightly forward, as hammer strikes at the high edge of recess, and doesn't strike flat on nipple :hmm: I eliminated 90% of misfires by simply honing the nipple with a diamond hone. All I had to work with at the moment :grin: I'll work on the face of the hammer when I have proper tools.

I had a similar problem one day and it turned out to be part of a cap stuck in the hammer.