doublegunshop.com - home Forums General Discussion DIY Gunsmithing @ doublegunshop.com info. on replacing outside hammers on sxs shotgun?

I am restoring an early W.C.Scott sxs outside hammer gun. One hammer is missing so I have decided to replace both. I have the hammers with the proper throw. I am not sure if I have the skill to fit them properly or to send the receiver out and have them replaced. Any help or suggestions would be helpful.thanx

I grafted these Chinese hammers onto a Stevens 225. (They look better after I cleaned up the grinding and stripped black finish with vinegar and aged with wet oak sawdust. )

I MIG welded shut the existing hole and drilled a new hole. Then used a square Swiss file to square it out. It was by try and error to get the angle right. I errored on one and had to do it over.

It took several hours and wasn't what I'd call easy. But I'm what people call a nut and will try lots of stuff other people wouldn't.

The gun was a $50 parts gun and the hammers came as part of a trade so the cost risk was low. There is not much chance of screwing up the action.

Are your hammers blank? Or off/for another gun? If they are blank hammers, you won't need to weld (unless you screw up). I lucked out and the hammers bent in perfect.

If you have the correct throw make a pattern out of cardboard to get the hole placement. You can either use a needle file to square up the hole, or I have heard the old guys would use a square punch that is the correct size and punch from back to front. Good luck.

The hammers are blank and my concern is getting the hammers hole squared off so the hammers set in the proper position to the firing pins. the card board template may be the way to start.i am interested in any help I can get on this project the sxs is too nice to mess up. It is being stocked at this point.

I am sure I have said how to fit hammers sometime in the past and it is a reasonably simple process if you don�t use files to cut the hammer mounting square. The reason for this is if you look at the square in a hammer boss from a working gun you will find that it has a small taper from the inside to the hammer outside, with the smaller section square on the outside very hard to accomplish with files. There is a very good reason for this taper because on the majority of locks the hammer mounting square is parallel sided. So if you have a tapering square on the hammer when it is fitted to the lock mounting square it will reach a position where it fits it tightly and as the hammer retaining screw is tightened this tightens the fit even more, and of course it can keep the hammer tightly fitting to the lock also allowing for future adjustments.
This is the reason that when you remove the hammer retaining screw the hammer very often will not just drop off you have to do a little levering, also on a well fitted hammer there is a slight gap between the top of the mounting square and the outside face of the hammer so there is no contact with the mounting screw head. If or when the mounting square touches the underside of the screw head the hammer will eventually become loose on its mounting and no amount of tightening the screw will help matters.
The way of fitting a hammer correctly is to swage the square mounting using a tapered Square hardened polished and oiled metal punch having a taper of between 2 to 4 decrees putting into a smaller hole than the mounting square starting on the inside of the hammer then driving it in. Doing it this way you can get the correct angle for the hammer mounting compress and work harden the metal a little also you can continuously try the hammer fit on its mounting square during the whole process.

Damascus, thank you for properly explaining the process I have not done, but read about.

Is this process still in use in G.B. The replacement hammers are not drilled for the hammer mount. One of my problems is figuring out how to align the two hammers to be in line with each other and also to set in the proper position in relation to the firing pins. the hammers are of the proper throw.

Pilot the hammers with something like a 4.5mm drill bit then swage it out to the proper tapered square, i used some 5mm x 5mm tool steel to make the punch filing a taper into the 5mm x 5mm blank and filing it to round at the end, that way you can put the tip of the punch into the pilot hole and visually put the square edges of the punch in the correct orientation on the hammer in the down position, or full cock position, then just hammer the punch through swaging the hole to square.

This method will give a very good tight fit, make sure you castings are annealed soft and you punch is good and hard.

I have used this method to fit replacements to two pinfires and a percussion gun, with great success.

If you mess up or are unhappy you can weld the hole up and try again, i have had to weld two up and refit them, only because the orientation was slightly off on one hammer, and on the other one i had previously tried to fit by filing a square hole.

Pod this swaging method is the correct way to fit an external hammer to a gun and has been used for well over two hundred years irrespective of the country, as the saying goes if it ain�t broke don�t fix it. Though there is only one other method I know of and was used by some makers on heavy recoil guns, this is both the gun lock mounting square and the hammer mounting square where both tapered giving a larger hammer to lock square mounting surface area and in doing so it acts like a full length taper fitting.
How to orientate the hammer? Well the easiest way is to make a template that fits to the lock square. This consists of a disc of metal roughly 1/8 inch thick about the average size of a hammer mounting boss with a square hole that will fit the mounting square (you can file this) to fit. Next you cut a rough hammer shape from another piece of metal but having a mounting hole that is round and will rotate around the mounting square. Then you fit both together by drilling two holes one above the other below mounting square, thread the round disk holes to take machine screws but the hammer shaped piece you make extended slots so it can be rotated. To use it you fit it on the locks square then rotate the hammer shaped piece to obtain the correct angle and distance from the firing pin, tighten the two screws to stop any further movement and this will give you the correct orientation of the mounting square to the hammer to the hammer boss.
I hope this makes sense in the end it is just an adjustable hammer. It does not have to look like a hammer as long as the face that strikes the firing pin is the correct angle.

Damascus:
Thank you for the info. Not being the sharpest knife in the draw I think I can still figure it out if not I will contact you .