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General discussion => Gun Building => Topic started by: DaveP (UK) on February 28, 2013, 01:45:09 AM

Title: Bending a percussion hammer?
Post by: DaveP (UK) on February 28, 2013, 01:45:09 AM
I'm in the early stages of trying to unite a percussion pistol barrel and lock in a scratch built stock and I have a problem.When I offer the lock to the barrel it appears that the hammer is not going to strike the nipple squarely.
It's an Enfield pattern lock, and the hammer is a complex shape, the shaft bends towards the barrel and the head is also set on it in a "nose in" configuration.This brings the hammer over the nipple but viewing from the front reveals the misalignment.
I reckon that all I need do is to bend the top of the shaft a little more, but I'm not sure how to do it. I think the hammer is cast steel, and I would expect that bringing the area I wish to bend to red heat would be the way to go, but what afterwards? Is it enough to simply let it cool down in air, or would I need to carry out some form of heat treatment?

I'm also having trouble deciding whether to try this right away, working by eye, or to wait until I have inlet the lock plate - by which time I would have made decisions which could affect the striking force... Any thoughts would be most welcome!

Title: Re: Bending a percussion hammer?
Post by: Hungry Horse on February 28, 2013, 05:09:37 PM
 I would heat the hammer red hot, with a torch, while holding the main body of the hammer in a vice. The best tool for making the actual bend is the box end, of a box end wrench, that fits over the hammer nose. Making a wire model of the angle the hammer needs to be, to make good contact, is the best way to get it right the first time.

                        Hungry Horse
Title: Re: Bending a percussion hammer?
Post by: rich pierce on February 28, 2013, 06:07:12 PM
Great advice on the wire mold!  That's a keeper.
Title: Re: Bending a percussion hammer?
Post by: SuperCracker on February 28, 2013, 08:05:33 PM
Great advice on the wire mold!  That's a keeper.

X2 !!! 
Title: Re: Bending a percussion hammer?
Post by: D. Taylor Sapergia on February 28, 2013, 09:05:11 PM
I have had to adjust the nose of percussion hammers many times.  I drilled and filed a hole in a piece of 1/4" steel flat stock that fit perfectly over the hammers I was adjusting.  Then red heat from an oxy/acet torch with the base of the hammer in a vise...slip the 'wrench' over the nose and move it where you'd like it.  Obviously, you can only go so far.  Sometimes one needs a different hammer with more 'reach' or one that lays over the breech farther and is not so straight up and down.
Title: Re: Bending a percussion hammer?
Post by: DaveP (UK) on February 28, 2013, 11:44:01 PM
Thanks. Wire model - Brilliant!
Its also good to know I'm not about to do something outrageous. And I've decided for myself to inlet first. If I have to replace a small piece of plain walnut - so be it.
But my question about "aftercare" was quite serious, my metallurgical knowledge is limited.
If I simply leave it to cool afterwards, will that be OK?
Title: Re: Bending a percussion hammer?
Post by: D. Taylor Sapergia on March 01, 2013, 12:31:14 AM
Yes.  The hammer, if it came from an original lock, probably was case hardened.  You'll lose a lot of that when you heat it red, but it doesn't matter to the hammer.  It'll still function fine.  So after bending, just let it cool slowly.
Title: Re: Bending a percussion hammer?
Post by: SuperCracker on March 01, 2013, 01:24:02 AM
How are you guys getting the face of the hammer back square to the nipple after you bend the hammer?  I never could figure out  a good way to do that. Or are you guys even worrying about it?
Title: Re: Bending a percussion hammer?
Post by: snowdragon on March 01, 2013, 04:47:23 AM
When I bend a hammer, twisting the nose so that it's square with the nipple is part of the process. I like to use a small oxy/acet torch so that I can heat small areas for more controlled bends. Sometimes it takes lots of little bends to get it just right, but I haven't missed yet. A small crecent wrench is my tool of choice, but I may try a box end wrench on my next project. Bill
Title: Re: Bending a percussion hammer?
Post by: D. Taylor Sapergia on March 01, 2013, 04:48:19 AM
If a hammer's face, where it strikes the nipple is not correct, I use a special drill bit ground flat like an end mill, and tapered so as not to make the cup weak.  I like to do it too, to make the hammer nose come down farther on the nipple.  It's easy to do.
Title: Re: Bending a percussion hammer?
Post by: shortbarrel on March 02, 2013, 01:44:16 AM
seen many rifles, first hand and on the ALA museum.  many of then hit the the cap at an angle, not my way of doing things. i guess it works,but i would call it poor craftsmanship.