I have a hammer for a long-range muzzleloader that I want to checker using a checkering file. The spur has a complex set of curves that make it difficult to imagine how to jig up something that would serve as a fence or guide for the file and freehanding it just doesn't seem to be too promising, esp. as a first attempt.

Does anyone have any experience with this? Let me rephrase this, probably 2-3 dozen of you have done this a hundred times. I'd really appreciate knowing how you do it. I could make up something but reinventing a wheel that might be only half as good as something tried and true seems like a folly. Any suggestions would be really welcome.

Thanks.

go buy a thread file that has the TPI you want. Heat it red hot and let it cool slowly. Once cool it will have no temper. Use a 3 corner file and file each row of teeth so each row comes to a sharp point at one end of the teeth. After each row is finished. reheat the file to red hot then dunk it in a can of oil until cool, re-heat until a dark blu colour and dunk in oil again. File should now be hard enough to mark a pattern of lines on the hammer so you can finish up the diamonds with a small square file

Have that job coming up. Can't figure out how to use a file up against a border. Usually use a threading file for spacing and cut the checkering with an engraving tool(90° graver) and a small hammer.
Chuck

Well, after some thought and consideration, here is what I built and how it worked.

Overall, I can see a couple of ways that it can be improved, but it got the job done. Next time, however, I think I'll follow Jim Westberg's advice, "that's what engravers are for".

The checkering file is used for spacing, but will take much care.Lines should be extended/completed with 3 corner or square file(small).
Mike

Yup to all of the above.