Shimming a hammer

[deermanok]

I need to shim the hammer on one of my rifles. Does anyone have any advice on the best way to remove the hammer? I was told to remove the screw then gently tap it out.

 

[bang]

What makes it need a shim?

 

[deermanok]

What makes it need a shim?

The hammer drops on the nipple ok but with a cap on, it hangs up on the cap. The hammer needs to move about 1/16 inch to the right to clear.
Looks like when they cut the mortise for the lock, they went a bit too deep. I tried to shim the lock out a bit but not enough to fix the problem. Shimming the hammer seems to make sense now.

 

[Phil Coffins]

Shimming isn’t the answer, the hammer needs bent to strike the nipple correctly.

 

[Grenadier1758]

Admittedly, bending the hammer is the recommended method to align the hammer. The square shaft on the tumbler is tapered and shimming the hammer out may loosen the hammer on the tumbler unless one peens the internals of the hammer to tighten the fit on the shaft.

To remove the hammer all the parts on the lock plate need to be removed. Take the lock apart in a box to keep all the small parts in the general vicinity of where the lock was taken apart. With the lock plate, tumbler and hammer left together take the lock plate to the vise with the tumbler resting between the jaws of the vise and the lock plate resting on top of the jaws with the hammer up. you need a round punch about the same diameter as the distance across the flats or better yet, make a square punch the same size as the square post on the tumbler. Gently tap the tumbler out of the hammer.

 

[deermanok]

Maybe I should try bending the hammer. It doesn't have to move very much at all.

 

[Zonie]

If the problem is a side to side issue, figure out if the hammer needs to move out away from the barrel or in towards it.
Then, remove the lock.
If the hammer needs to move in towards the barrel, get a sharp chisel or knife and lightly scrape the shoulders or surfaces at the top of the lock mortise that the lock plate rests against. There are usually several places in that area that the lock rests against. Then, retry the lock in the stock. It doesn't take much material removal in the lock mortise to move the hammer quite a lot.

If the hammer needs to move away from the center of the barrel, scrape the surfaces or shoulders at the bottom of the lock mortise.

To give an example of how little of the amount of material that needs to come off, I've seen several guns that had a problem and scraping off the varnish the company sprayed into the mortise was enough to fix things.

 

[bang]

Does the lock plate fit negative in the opening?
Taking it it's a r/h shooter. If it fits negative you might start by shimming it out to flush to minimize hammer adjustment.
Minor adjustment of hammer a common thing. I put it in vice between two pieces of wood clamped full on where the hammer attaches. Get an index point. Tap the striking end of the hammer with a mallet. Check index point for movement. If it moved maintain that impact pressure and repeat slowly untill index point indicates needed movement. Only use enough impact to move it slowly. Too much movement at once could crack or break it. If it's real stubborn some heat may be needed.

 

[deermanok]

Thanks for the help. Like I said, the hammer doesn't need to move much. With a cap on the nipple, the right side of the hammer cup just touches the cap enough to hang up. When I had the rifle at the range last week, I had what I thought was a misfire. The hammer didn't make full contact with the cap. Out of 15 shots, it happened twice, so it's not a huge problem but still, I wouldn't want it to happen if a deer was standing in front of the gun.

 

[Col. Batguano]

When you bend it, do it when it's orange or yellow hot. Quench in a light oil like salad oil. Then temper it for an hour in your oven at 375F. Here's a link for you.
https://en.wikipedia.org/wiki/Tempering_(metallurgy)

 

[rich pierce]

I don’t understand how the lock inletting can be changed at all. The lock is inlet until the bolster rests against the barrel. It cannot be inlet less. It cannot be inlet deeper. Bending the cock on a percussion lock is nearby always required.

 

[jerrywh]

Bending hammers is a standard procedure.

 

[deermanok]

Thought I'd put up a picture of what I'm up against.

 

[deermanok]

Without a cap

 

[bang]

Won't take much.

 

[stink koat]

Or you could use a dremel w/small mounted cylinder style grinding stone and take some material out of the hammer where it is hitting the cap/nipple. Had to due the same on a rifle that my great grand nephew was building. NOT A BIG DEAL to gitten er done!

 

[ohio ramrod]

As mentioned there are several ways to solve the alighnment problem. Simplist and easy to "undo" if needed. place a thin strip of shim stock along the top of the lock inlet tilting the hammer out.,2. Put a thin shim between the lock and hammer ,requires removing the hammer and making a shim with the hole in it. 3. Bend the hammer, requires removing the hammer and heating to prevent breaking. 4. Use dremmel to enlarge the cavity in the hammer, can not be "undone". So chose your method.

 

[Col. Batguano]

Or you could remove the drum, get a new one and re-drill. Possibly the old one could be plugged and the nipple re-drilled too. Drums are only $15 or so.

 

[deermanok]

I ordered a mainspring vise from muzzleloading emporium, which I got in the mail yesterday. This morning, I was able to disassemble the lock. I used one thick plastic shim from a kit and that solved the problem for me. Got the lock back together, everything lines up just fine now.
Hope to be at the range by the end of the week. Thanks all for the help.

 

[Flintandsteel]

Looks like a shorter nipple just might cure your problem.