I got a new hammer from the Rifle Shoppe, managed to drill the hole in the right place, and fit it to my action. My question is do I need to harden the entire hammer or just case harden the sear notch or leave it as is?

THey didn't specify, but it was easy to drill and file to shape.  I'll do the entire hammer as you suggest. Thanks

jhm wrote on Apr 6^th, 2025 at 10:52pm:


Hopefully Ken Moss will see your post and reply. He knows all the screw sizes since he made screws for almost all single shot rifles. If he doesn't, I have brand new screws I can try and do a thread count gauge on, and measure diameters with my micrometer.

jhm wrote on Apr 6^th, 2025 at 10:52pm:


Here’s the drawing of the block screws.   

I tend to make screws to what I have on hand and custom lengths and diameter for best fit.   

Not sure these drawing are correct in comparison to actual originals.  Obviously the bb link and lever screws are different.  My hand drawing are what were used to fix an actual original.

Be interesting to see what Ken has.
Bob

That series of drawings is suspect on many details.  Good hints, but not definitive.  The screw sizes were modern "equivalents" that were close, but not necessarily interchangeable.  The guy that reverse engineered them used to post here occasionally, his name was Frank something if I recall correctly.  He was a draftsman, not a machinist, and did the takeoffs from limited examples, maybe even 1.   

On the hardening question:  Yes, the hammer needs to be hardened throughout, not just the sear.  The nose of a hammer needs hardened and then drawn out moderately.  Otherwise it will mushroom and deform in use.  You can draw the hammer nose out more than the sear by polishing the metal bright and heating the hammer nose until it's the appropriate color, (I'd go medium straw, just as purple starts to appear.  Or use temperature crayon, and use the appropriate temperature for the material you're treating.  The heat conducted to the sear notches won't make them as hot; you can draw them out by themselves, but you want to keep them pretty hard.  Maybe not glass hard, but close.  I've had them chip if I didn't draw them out slightly.

got my  prints out. but most of the screw sizes on those prints are off from what I came up with the hammer and lever  are .227X40 no tap found. lock screws fore arm screw tang sight screws lever link screw .172 X 40 closes tap is a 6X40 STI tap like in heilcoil. trigger plate screws are .135x42. no taps found. what I found is that Red River and Cody used off the shelf taps to biuld there guns Ken

Not looking for original fastener sizes cause as you stated you probably couldn't get the taps and dies. I am pretty sure I have both 12x40 and 8x40 taps and dies so thanks for the tip. Going to get started tomorrow. Been cleaning up all the individual parts of sprue and casting lines etc. Rodney casts a good part. I hope the person who bought him out will give as much attention to detail as he did. Thanks for the help.


JMH

All the block screws and one of the link screws are the same threads. Just different lengths, and on the link screw a different length and head. Hammer screw and Lever screws are each unique size and length.