CJ, Don't take this is any way as a critique; Seeing springs cut out of solid bar stock like that goes completely against all of my springmaking sensibilities! I think of springs as forged and bent with the grain running the length of the flex.
These look like an extraordinary waste of material with all the wrong grain structure. Are they pre-hardened and tempered?
Now, I've got to admit I used investment cast steel spring in building and shooting flintlocks for a couple of decades, and I can't ever remember a Siler mainspring breaking! Siler being the most popular flintlock ever made, original or reproduction.
But what an advantage for making/replacing a spring! Modern metalworking is genuinely beyond my ken....
